Design Log.mp2

== Multiplayer-Evolution II Ruleset (MP2) Design Log ==
This page details the changes to the Multiplayer II compared to the original Multiplayer ruleset through the first two releases of MP2-Avant Garde and MP2-Brava.
=== Other MP2 Resources: ===
* See Multiplayer II Navigation Page
===DESIGN LOG and DETAIL LIST ===
Each item gives an Explanation and short summary of changes: the Effect on game play.
==I. Technologies==
==1. Tech costs changed==
Explanation:  Formerly, a formula did tech costs. It did well until late-game, then tech pace was too fast.
Effect:  First techs cost 4 bulbs less. After this, techs are generally the same cost as before until the tier with Banking & Monotheism, where most costs rise ~10%-15%. All bulb costs go up +25% from the Democracy/Gunpowder tier onward, and are generally another +5% for each major tier after. Last techs are +50% except the "final tech" Stealth is double. After mid-game, new units can be featured and used without becoming obsolete too fast.
== 1a. Tech holes closed ==
Explanation:  Formerly, allowing tech holes allowed interesting creative strategies. However, it became a constant battle to tune out exploits, and attention and focus on elaborate "tech hole management strategies" began to take up far too much attention and impact on expert play.
Effect:  To acquire a tech absolutely requires first possessing all the pre-requisite techs.
==2. Voyage of Darwin==
Explanation:  Changed to increase Trade like Colossus. Cost: 200 shields. In MP1, "collective Darwinism" could finish the tech tree on 0% science. But making it One-player-only violates Multiplayer's ReWonder design principles. Darwin now becomes a replacement for Colossus going obsolete, and represents a breakthrough in trade, technology, and products.    
Effect:  Previously, most late-game tech was not used: it was replaced too rapidly. Now, the late-mid-, early-late-, late-, and end-game are exciting new phases of the game that can be experienced and enjoyed.  
== 3. Restricted Abuse of Philosophy ==
Gives a free advance but coalition abuse is curbed.  Free tech awarded if discovered before Turn 85 (1600AD), but only if the player has none of the following:  Banking, Invention, Physics.
Explanation:  This solution preserves the function of Philosophy while not breaking original MP design goals. Some who were unaware of MP's design goals wanted to eliminate Philosophy bonuses. They were justified in disliking how Philosophy accelerated the late-game with “tech gangs” discovering more advanced techs than nations with scientific infrastructure. But “Philosophy for Everyone” was an important component in re-balancing changes to trade routes. It had the added advantage of enhancing the game design goals: each civilization selected a 'breakthrough' tech it wanted, to define its civilization and strategy. Noobs, late-joiners, and the majority of players in the world of massive multiplayer use Philosophy as a bargaining chip to be relevant and get influence, alliance, and protection. It lets them have a chance to survive and learn to play. This solution met requirements to balance all the points above.   
Effect:  Before 1600AD (T85), Philosophy gives bonus tech if you do not have any of the techs belonging to the tier right after it. This lets Philosophy be used as intended. It keeps the component of defining your civilization's special traits and strategy, diplomatic scheming, and adds strategic depth and unpredictability. A very important design precept is preserved: to use Philosophy and Marco Polo to compensate trade route changes. Game notifications begin warning players of the coming expiration on T79.
==4. Space Flight gives a vision bonus==
Unit and city vision increase.
Explanation:  In Classic rules, the Apollo Wonder gave full vision, but it was removed from Multiplayer because it was OP for a single nation to get this power. This re-introduces the excitement of acquiring Space Age tech and vision bonuses, equally for all.  
== 4a. Space Race tuned as a viable game option ==
6.25x cost increase for spaceship parts. Server option spaceship_travel_time is adjustable (default=225%).  
Explanation:  Spacerace was previously disabled in massive multiplayer games, because it was too cheap to make a spaceship, and the travel time too short for other players to react. Greater cost and travel time make this a viable setting again. It can force an end to late game stalemates. By allowing a single lone wolf to win, it gives a counterbalance against victories from dominant alliances. It may introduce more diplomatic intrigue, since there is no allied victory in spacerace endings. Thus, spacerace can become a geopolitical instrument, and perhaps has other strategic uses.  
==5. Electricity removes Fog of War inside your own borders==
Explanation:  Electricity allows for lights. 
Effect:  The default borders setting for multiplayer games is SEE_INSIDE, in which case this change makes no difference. The reason SEE_INSIDE was always used is because the 2x:1x movement:vision ratio could exploit poor border vision. MP2's recalibrated vision now allows new possibilities. There is now an alternative to use /set borders ENABLED, which does not automatically give you vision of every tile in your borders. If using this setting, it provides an alternative to allow games that have a "Dark Ages" for the early game. Such games would have less comfort or certainty to "rush through" the early ages of history, but slowly reveal more as technology such as Physics and Electricity start to reveal greater vision. Ancient and feudal warfare might become more common. (When making units to counter against possible unseen invaders, you might see if you can use them instead of have them sit idle.)
== 6. Horseback Riding before 2500 BC creates traveller's tales ==
Explanation: 2x movement gave the Stone Age a major flaw. It was possible for an unskilled novice to rush for Horseback Riding and do a mindless "Horsemen suicide" to eliminate any nation who did not use the same strategy. Any unskilled player could sacrifice his nation to destroy one other nation. This creates a Mexican standoff paradox: more players make horsemen first, causing even more players to make horsemen first, ad infinitum... Any player who didn't make horsemen first made it through the early game only by pure luck. Six historic developments had caused this: (1) 2x movement halves travel time, (2) To reduce map size, massive multiplayer games reduce "tilesperplayer", (3) Thus, number of vulnerable targets are increased by more than 4x, (4) First tier techs cost less, (5) Longturn games begin with more starting gold, and give "latejoin gold", (6) To speed the early pace in longturn games, disbandable units are given to supply extra "starting shields" for first production.
Previously, many more horsemen could be produced much earlier and travel much faster to expose over four times the number of vulnerable targets. This distorted early-game strategy and gravely corrupted the luck/skill ratio. The Rochambeau formula of "attack vs. defend vs. farm" should be restored to its former balance.
Effect: This subtle fix successfully achieves the goal of not changing any game mechanics or unit stats. Instead, players who rush Horseback Riding spread tales about their tribe's impressive ability to ride wild beasts. As always, a nation who chooses one of the other six strategic tech paths will still be disadvantaged when more Horsemen arrive earlier and faster to targets they couldn't reach under 1x movement. Yet "Traveler's tales" discourage the negative feedback loop which made more players feel forced into "Horsemen-first." The public warning re-balances reaction time to be closer to 1x rules. The game becomes more playable and gains the element of Stone Age civilizations excited to learn more about their dark world, through the exciting tales of travelers.
==II. Government==
== 1. Fundamentalism adapted ==
Adapted for better balance, viability, fitness, and distinctive character.
Explanation: Formerly, this government had been "pasted in" from other rulesets. It was not well fitted with the MP ruleset. It was less competitive even in the special strategic contexts for which it was intended. Fundamentalism gets a significant number of changes, all of them beneficial. All of them enhance the distinctive role for this government. Fundamentalism becomes more viable for alternative strategies and special strategic contexts.
Changes:
* Cities: Empire base/step size goes from 14/12 to 14/15 (see governments.)
* Settler food upkeep changed from 3 to 2.
* Capital Production Bonus is +50% gold output. (City with Palace.)
* Ecclesiastical Palace: confers to its home city +1 veteran level to Fanatics and +50% gold output
* Fanatics can't be bribed.
* Fanatics can do 3 combat rounds of free skirmish assault if inside domestic territory.
* Was only government with neither martial law nor rapture. Adjustments:
** Gets limited Martial Law. 2 peacekeeping units cause 1 content citizen each.
** Gets Pilgrims. Cost:10 Pop.cost:1 Moves:2 Upkeep:2 food. Pilgrims accelerate population growth and facilitate population redistribution. They cannot do Worker tasks like Proletarians, but like Fanatics, they have no upkeep so long as they remain under a Fundamentalist government.
* Enemy nations can't establish an Embassy without first getting cease-fire, peace, or alliance.
* All Sabotage-type actions have a 10% higher chance to succeed.
* Production waste (from corruption) was alien to the ruleset and trivial. It was removed.
* MP2-Caravel 1.2 onward: Fundamentalist governments gain access to Partisans from Guerrilla Warfare.
== 2. Communism adapted ==
Adapted for better balance, viability, fitness, and distinctive character.
Explanation: Rules adjustments for massive multiplayer had disadvantaged Communism somewhat. Universal availability of Small Wonders allowed Democracy to enjoy an increase in its advantages AND eliminate the disadvantages it once had relative to Communism. To re-balance, Communism gets a small number of changes. All of them are significantly beneficial. They enhance the distinct character that was intended for this government. Communism is now much more viable for alternative strategies and contextual use. And more fun!
Changes:
* 4 units free of upkeep per city (was 3.)
* Capital Production Bonus is +25% shield output (was 0.)
* Buildings with 1 upkeep are free; this effect compatibly accumulates with all other bonuses.
* Proletarians. Cost:10 Pop.cost:1 Moves:2⅑ Upkeep:1 food. This is a citizen under full state control. It may be used as Workers for mass labor, or to accelerate and re-distribute population growth.
* The Communism tech allows Communist governments to convert Workers to Riflemen and vice versa. Conversion time: 1 turn. *(Unit must be in national territory. Nation must possess the necessary technology for the converted unit.)
* MP2-Avant Garde: Riflemen cost 5 less for this government.
* MP2-Avant Garde: Dive Bombers cost 10 less for this government.
== 3. Foreign Nationals added ==
Citizens in conquered cities keep their original nationality. If the conqueror is at war with their homeland, 1/3 of them will be unhappy. In newly conquered cities, this gives an advantage to governments with martial law. Citizens assimilate over time to become the nationality of the conquering nation. 
Explanation: Unhappy foreigners are trouble for governments which lack martial law. This restores some of the originally intended character of the game by balancing some side effects of MP1's ReWonder 1.0.
Effects:
* On conquest, one third of citizens will convert to the conqueror's nationality, or a minimum of 1.
* Enemy Unhappiness: one third of foreign citizens are unhappy if the conqueror is at war with their nation. This forces: a) higher national luxury, and/or b) entertainers, c) martial law, or d) temporary disorder.
* Conversion: Each turn, one foreigner will convert to the conqueror's nationality.
The chart below gives an illustration of how these 3 factors affect a conquered size-18 city over time:
==III. Units==
Combat units get 3 more vet levels. These give modest increases and +⅑ move point over standard.
==1. Vision adjustments==
thumb|220px|1.4x vision before Physics
Made to bring Vision/Movement ratio closer to 1:1 like in 1x ruleset.
Explanation: The ratio of vision/movement affects game play and tactics.  Rulesets higher than 1x movement typically adjust vision upwards in order to preserve proportional balance.  Consider the ability to see a unit which is 1 turn away from being able to attack.
Effect:   A typical 2x movement unit now has 1.4x vision instead of 1x.  Physics raises it to 2x. (Physics historically gave birth to telescopes and binoculars.) The ability to see where you're going and to see the arrival of enemy units is now closer to the proportions of original 1x rules. Please note there are also vision bonuses from Fortresses, Mountains, Lighthouse, and Space Flight.    
MP2-Avant-garde: Radar Tower and Radar tile improvement added. Req: Radar.
==2. Restrictinfra re-balance==
Enemy rails only act like roads, while roads can still be used by all.
Explanation:  A 'middle ground' compromise to Restrictinfra was achieved. Previously, our choice was between two extremes. Some claimed that it's ridiculous for armies to travel the world at light speed conquering dozens of nations in a single turn. Others claimed that making enemy rails and roads not even exist, was extremely unrealistic and even worse. Both sides were right.
Effect:   Late game strategy was dominated by justified paranoia that rail invasions from "howitzers at the speed of light" would end the game right before “the good part of the game” arrived. This is fixed.
===== *(Restrictinfra=OFF preserves Classic behavior settings.) =====
Also see: 3. Railroad move speed, below.
== 3. Railroad move speed ==
Changed to 9x, MagLevs available with Superconductors for unlimited moves.
Explanation:  It was imbalanced for industrial age armies to travel the world at light speed. Railroads now get a generous 9x movement, three times faster than roads. The MagLev terrain improvement was added because: 1) With the existing 9x rails, placement of MagLevs is a strategic choice: fans of infinite movement rails still get to have them if they want them. 2) MagLevs "shrink" the massively large worldmap in ultra-modern times. 3) MagLevs may cause ultra-late strategic shifts which disrupt status quo gridlocks. 4) Superconductors now has a tangible bonus for acquiring it, when previously it gave none.
Effect:   Improved domestic transportation. MagLevs are an ultra-late strategic tool.
Also see: 2. Restrictinfra re-balance, above.
==4. Bribe cost ==
½ cost correctly adjusted to include all non-military civilian units, not just Settlers.
Explanation:  Bribing civilians is easier than bribing military. The ½ bribe cost rule goes all the way back to when Settlers were the only civilian unit.  This fell between the cracks during version porting, resulting in Workers having the same bribe costs as military units. In reality, the most bribable unit of all is an underpaid worker. 
Effect:  Bribe cost decreases with distance from capital: workers far from home are realistic bribe targets. 
MP2-Caravel: Democracy can now be bribed but has 3x bonus for higher bribe costs. 
==5. Mountain Vision==
thumb|260x260px|Mountain vision before Physics
Land Units on a Mountain can see +1 tile.
Effect:   This provides more realism and tactics. The inferior 1.4:2 Vision/Movement ratio in the early game is compensated with a feature that provides more tactical richness.
==6. Nukes get 24 movement points==
Available later (Space Flight). Prior to this, "Atom Bomb" is available.  
Explanation:   The relationship between range and 'threat area' is not linear. A Nuke's “threat area” is a much stronger component of its overall power. Giving 2x movement like other units gives a 4x threat area (A=πr2).  24 moves was chosen, which is 1.5x range and a 2.25x increase to threat area: a good balance point for a 2x ruleset.  
Effect:   Nukes can reach 1.5x more range and 2.25x more area than in 1x Classic Freeciv. 
==Atom Bomb is precursor to Nuclear Missiles==
Explanation:   It was unrealistic and imbalanced that nuclear ICBMs were available one tech after World War era Bombers. Atom Bomb is now available with Nuclear Fission.  
Effect:  a) In the early nuclear era, 870 cost = Manhattan Project + Heavy Bomber + Atom Bomb. b) Range is limited by the best Bomber the player has available. c) Early use of nukes has more defensibility, since Bombers can be intercepted by Fighters.   
MP2-Avant-garde: Atom Bombs now only affect cardinally adjacent tiles.   
MP2-Avant-garde: nukes_minor server setting allows playing a game without nuclear weapons.
==7. Knights given two bonuses==
D3 vs. mounted; D2 vs. foot; D1 vs. other. Knights don't reduce population on attacked cities.
Explanation:  There are two reasons the Knight gets two small bonuses:  1. The Knight used to be the first mobile unit who attacked at 4. But then Classic ruleset added Elephants available much earlier. Polytheism led straight to Monotheism, giving a superior offensive unit and economic benefits. This minimized Chivalry's place in the tech tree. 2. Rulesets did not distinguish a separate class for foot units: mounted units' superiority against foot units was simply coded as higher overall attack strength against all units. But a defending Knight who is also mounted should do better than 6% survival against another Knight, since they are equally on horseback.   
Effect: Two small bonuses restore Knights to relevant usefulness and balance:  1. Knights defend at 3 against mounted units. This gives an equal chance of survival when attacked by a more primitive Chariot, and 26% against an attacking Knight. 2. Archers and Legions gain some validity. 3. Knights had historical noble vows to conquer towns without pillage and murder; this virtue often swayed allegiance by the citizens. Therefore, the Knight can attack towns without population reduction.  (Cities still lose 1 population when changing ownership, however.)
MP2-Caravel: Knights now cost 38.
== 7a. Legions improved ==
Legions can make Forts and Fortresses, and build roads inside them or on non-domestic tiles.
Explanation: Here are the reasons the Legion deserved two non-combat bonuses: 1) The combination of cost, slow speed, and more effective units, made the Legion lack value. 2) Real Legions were feared and famous for their highly disciplined engineering skills: on military campaigns, they rapidly constructed roads and bridges, and constructed forts nightly when on the march.
A slightly neglected unit needed a slight buff, but already had strong combat stats. Both balance and realism are improved by giving it the distinctive abilities which made it famous.
===== Legions only build non-domestic roads because 1) They were warriors, not domestic slaves, 2) Replacing Workers with an A4 D2 unit for +10 shields is OP. =====
Effect:  The new abilities transform this unit from a forgotten unit into a relevant and distinctive unit.
MP2-Caravel: Legions now cost 32.
== 7b. Archers get limited Range Attack ==
Archers gain the ability to volley one round of arrows on all units on an adjacent tile.
Explanation: There are two reasons the Archer gains a minor combat ability: 1) Like the Legion, slow speed and better unit options reduced the value of an historically important unit. 2) To provide more tactical richness, it was decided to give it a small but serviceable bonus that represents a realistic historical advantage.
Effect: Rather than engage a single unit to the death, Archers can also do a Ranged Attack with no risk of retaliatory damage: a single volley of arrows is fired over all enemy units on the tile, causing 1hp of damage to any units who are successfully hit. This is useful for softening enemies prior to battle, or for deterring an approach to strategically held locations. (Ranged Attack is not possible on Cities or Fortresses; they provide cover from incoming arrows.)
===== NOTE: This change showcases new server features to improve balance. The Archer had historical range advantage its contemporaries lacked. Ranged attacks for other units would come at a time when every unit has range capabilities. Those abilities are already reflected and balanced into their other stats. =====
MP2-Caravel: Archers now cost 24.
== 7c. Armor adjustments ==
* Armor has no penalty vs. Forts, and penalty reduced to 1.67x vs. Fortresses (was 2x.)
* Plastics upgrades to Armor II A:16 D:6 FP:1 HP:30 M:6 Cost:80. 2x defense vs. Missiles. Unreachable units can't block its attack on reachable units.
Explanation: Formerly, Armor supposedly enjoyed a brief period of strength. This period was usually missed because the prioritization of other techs was encouraged by the triple penalty of obsolescence of Barracks II, Sun Tzu, and Leonardo. After this hypothetical short time window that was usually missed, the game was left with a unit that had little purpose: it defends worse than Mech. Inf., it attacks at less than half the strength of Howitzers, and costs more than both.
To increase tactical richness, Armor ignores Fort bonuses. Against Fortresses, its penalty is reduced to 1.67x. These bonuses increase Armor's relevance. Also, Armor now receives a later technology upgrade. This reduces the heavy penalty for lost investment into a rapidly expiring unit. These 3 changes increase playability, tactics, and realism.
Effect: The addition of Forts as a requirement for Fortresses, in addition to Armor having no penalty against Forts and only 1.67x against Fortresses, softly boosts tactical usefulness. The upgrade to Armor II reduces the dead-end sacrifice of buying expensive units that rapidly expire.
Explanation II: Armor II fills a hole in late game tactical variety and gives an upgrade path that validates the use of its predecessor unit. Composite armor and ECM give 2x defense against missiles, and unreachable units can never block its attacks on reachable units, giving a tactical answer to certain exploits. Like Armor I, it retains the immunity to defense bonuses from Forts; but in addition, suffers no defense bonus against Fortresses. Note: A16 FP1 has 66% the attack strength of the A12 FP2 Howitzer.
Effect II: Armor II gives tanks a late game presence. It also gives Armor I more use –– the rapid expiration of Armor's value had discouraged players from building the unit.
MP2-Caravel: Armor II now costs 85.
==8. Bribe and Sabotage bug fix==
Aircraft, nukes, helicopters, and missiles can't be bribed or sabotaged.
Explanation: Developers made an “Unbribable” flag to fix this bug, but Classic and MP1 never received the fix.
Effect:  You can no longer bribe a nuke or cruise missile and turn it around to go attack the city it came from.
== 9. OneAttack flag deprecated ==
Helicopters and Bombers no longer lose all movement points after making an attack. OA-flag has been eliminated after historical developments made it go from bad to totally dysfunctional.
Explanation:   To understand the necessity of this change requires a long history and analysis.  A short version and long version are below:  
==== Short Version ====
Q: What went wrong with “OneAttack” (OA)?  A: OA was improvised after playtesting to nerf OP air mechanics in the original game, limiting multiple attacks with no chance of retaliation and letting Fighters intercept Bombers and Helicopters on the same or next turn. However, it was an imbalanced hack. Instead of a subtle nerf to limit units to attack once, or to allow Fighters to intercept, this implementation caused a mega-nerf. Civ2 players renamed "OneAttack" with the more accurate name of "AttackOnceAndWaitForDeath." A Bomber was essentially paralyzed after an attack and vulnerable to an easy kill by a much cheaper enemy Fighter. OA-units were nerfed so much that experts rejected them. In Freeciv, changes to the server, play format, and play-mechanics, made OA go from really bad to absolutely dysfunctional.
==== Long Version ====
Freeciv has inner contradictions: it is a turn-based game and not conducive to RTS, but tries to simulate battles where interception, reinforcement, and other timely reactions are fundamental. This creates key issues that are difficult to solve. The OA-flag was a failed attempt to tune one of those issues. The issue was: turn-based movement allowed powerful units like Bombers to attack, kill, and return to safety: with the only opportunity for interception being spontaneous RTS from the other player. OneAttack attempted to mitigate the problem by nerfing units that had high movement and strong attack. But instead of being limited to only one attack, these units were forced to lose their turn after an attack, in order to allow non-RTS retaliation. The results? a) Units attacking at less than 10 (Fighters and Stealth Fighters) became more powerful than the more expensive Bombers. b) Helicopter, Bomber, and Stealth Bomber lost more than half their originally balanced value, but kept their original costs.
OA-units still held surprise tactical use in a semi-RTS environment of 3 minute simultaneous turns. On rare occasions, they were useful in spite of their overpriced ineffective in-game stats. Why? Because of time/focus/attention dynamics. OA units retained a degraded usefulness inside the little “cracks and holes” of an environment where you had to quickly make your moves in a rushed format that didn't give the opponent enough time to react. These units were no longer what they were supposed to be. They only had a use with a quick RTS attack and immediate GOTO seconds before TC. These units depended on an RTS environment in order to be useful. At the end of the day, OA-units lost all moves after attacking, could attack far LESS times than cheaper units, suffered an extra turn of waiting on unit healing (a -33% reduction in net offensive productivity), and worst of all: they were exposed to the near certainty of instant death retaliation from much cheaper older tech units. This made them worse than cheaper units, at double the price and with forced unhappiness! Implementing OneAttack as "AttackOnceAndWaitForDeath" was not subtle a fix. It made stronger more expensive units vastly inferior to weaker cheaper units.
But then it went from bad to worse...
Two things made OA-units go from bad to extinct.  1) Longturn became one of the preferred formats for expert play.  2) Server Version 2.3 introduced UWT to lessen RTS issues. 👉🏻 “AttackOnceAndWaitForDeath” + Longturn + UWT was a multi-headed monster which robbed the late game of what was already a scarcity of diversity in the number of usable units. Even though it had been originally designed to be more tactical, the late-game became the least tactical part of the game, resulting in blunt stack wars consisting of Howitzers, Mechanized Infantry, and [Stealth] Fighters.
==== Status report on correcting issues arising from OneAttack and/or its removal: ====
* From MP+ 1.1 onward, no units in the game have the OneAttack flag.
* From MP2 Avant-garde onward, the Vigil order fixes one of two reasons for the OneAttack flag: interception/retaliation.
* From MP2 Dragoon onward, "MaxAttacks" limits the other reason: multi-attack "kill binges" from high-power high-move units. 
== 10. Air unit ZoC and Unreachability ==
* Fighter type units do NOT exert ZoC: they do not prevent units from going to adjacent tiles.
* Other Air units do NOT protect land units on the same tile from being attacked.
Explanation:  Previous rulesets gave two options. Fighters could be: (a) defensively worthless – a Fighter couldn't provide defensive ground support, unable to even protect units from a Warrior, or, (b) overpowered and unreachable – a single Fighter could block 60 Howitzers from a Worker. Multiplayer ruleset chose option (b). This was always a dirty compromise. Defensive air support is represented by the Unreachable effect, even if it allows occasional exploits. Exploits are more rare than the need for defensive air cover, and that's why we need option (b).  But if we choose option (b), is it smart to aggravate the exploits? Trimming ZoC removes 8/9 (89%) of the abusive exploitation inherent in option (b). Special abilities in other units are used to tune down the remaining 11%.
On the other hand, it was ridiculous for an AWACS or a Bomber in a stack, to prevent land units from engaging each other. Formerly, Freeciv server forced all Unreachable units to be equal in whether they protect a tile or not. To get around this, MP2 takes advantage of the new "NeverProtects" unit flag. This lets MP2 set non-Fighter Air units to remain unreachable yet not protective of other units on the same tile.
Effect:  (1) Fighters can't exert ZoC over unoccupied tiles. (2) AWACS, Bombers, and Balloons are Unreachable but do not protect other units on the same tile. Other land units on the same tile may be attacked and killed from underneath them, while the air units remain untouched and unreached. (3) Fighter types are unreachable and protect their tile from other units who can't reach them†.   
† Except for "NeverBlocked" units: Marines, AAA, Armor II, and nuclear weapons.
MP2-Avant-garde: zoc_purity now disallows igZOC units like aircraft from negating ZoC rules for normal land units.
==11. Para-drop for Paratroopers adjusted==
2x area coverage. Para-drop range corrected to 14. (Was 10.)
Explanation:   Accidentally keeping Para-drop at 1x range had made Paratroopers weak in MP 2x rules. Range was raised from 10 to 14, which gives 2x more target area than MP 1x. 
Effect:   With 2x target area, Paratroopers become a relevant late-game unit for a 2x move ruleset.   
==12. Multipurpose Marines==
Can attack FROM air/land/sea TO land/sea; able to bypass air units to attack other units on the same tile. Better vet/promotion rates.
Explanation:  A buff to a single unit solves 3 problems:  1. Simplistic game mechanics caused exploits and gaps in tactical possibilities. 2. Air units' Unreachable-flag was a little bit OP and exploitable. 3. The strongest foot soldier in the game was not an upgrade over the Alpine in defense nor over Cavalry in attack–it comes much later than both and moves much slower than both. Its usefulness also expired much sooner. Except for a short window where it might be useful in amphibious attacks, it was inferior. This made a void in late-game foot units. 
Marines have a mission of Land/Air/Sea in the lyrics of Hymn of the U.S. Marine Corps: “From the Halls of Montezuma, to the shores of Tripoli, we fight our country's battles, in the Air, on Land, and Sea.” Marines are trained for Land/Air/Sea warfare with diverse weaponry. Freeciv suffered from: a) expired use of foot soldiers, b) no all-purpose unit to patch exploits and broken mechanics, c) unrealistic exploits in Land/Air/Sea interaction, d) Marines were overpriced, under-powered, & expired too soon. One elegant fix now balances many facets of the game.
Effects:  Marines can attack sea units, attack from Helicopters/Transports, and bypass unreachable air units to attack other units on a tile. Marines attack at half strength against Sea units. The above abilities help solve exploits that were abusive when the exploiter knew it was impossible to counter. Marines may not attack Submarines. 
Unrealistically, special ops like amphibious assaults were viable only in a short time window. To represent the arrival of modern weaponry, Marines made in cities with Barracks III and Airport and Port Facility gain +1 vet level. To preserve their balance improvement & "special ops" into the late game, Marines promote more easily: higher vet-bonuses from v3 onward. Marines thus get continued viability in the late game, yet are unchanged in strength when they first arrive. See this section of the online Manual.
MP2-Avant-garde: The +1/9 "ultra-elite move bonus" for v4+ vet levels starts to take effect in v3 Marines, since v3 is when Commando bonus begins.
==13. Escort Fighters added==
 A:3 D:5 M:18 FP:2   Fuel: 2 turns.   Cost: 80 shields.
Explanation:  Lack of diversity in air units hurt tactical variety. Lack of Escort Fighters left Bombers overpriced, defenseless, and never used. The Escort Fighter is a twin-engine defensive Fighter with larger size, fuel capacity, and damage absorption. It's better for defense and long-range missions on weaker targets. It can accompany a Bomber and escort it home on the next turn. It can give defensive ground support across a Turn Change boundary.
Effect:  The higher cost and weaker attack of this unit means that standard Fighters are still king of the skies. The Escort Fighter is useful for other strategic purposes, like escorting Bombers. This unit helps air combat go from a one-unit game of checkers to a multi-unit game of chess. This is a specialized unit for long-range runs, escorting bombers, and giving ground support.
Like all Fighter-types in all MP rulesets, the Escort Fighter prevents land and sea units from attacking the tile it is on. This unit has Stack-Escape. 
MP2-Avant-garde: All fighter-types can now do the new Vigil command.
==14. Medium Bombers added==
 A:7 D:2 M:15 FP:2   Fuel: 2 turns.  Cost: 85 shields. Cargo: 0. 
Explanation:  Unlike later versions of Civilization, Freeciv lacked a balanced diversity of Air units. Fighters were used to bomb land targets, while Bombers were ineffective and little-used. In between the Fighter's A:4 and the Bomber's A:12 was an empty void. The Fighter became the only Air unit in the sky. The Air-game was more like checkers than chess. The Fighter was rarely used for Air-to-Air and mostly did bombing. Then the arrival of stronger ground units made air attacks diminish until the arrival of Stealth.        
The Medium Bomber is one piece in a grand holistic solution to all the above. The Medium Bomber is able to continue Air wars through the late-mid game. It also gives the Fighter a longer life-span as the premier interceptor and counter against the Medium Bomber. It is a "soft field unit," which means if it is not aggressively deployed, it causes one less unhappiness than normal field units.      
Effect:  Tactical balance is restored. The lower cost and lower unhappiness from this unit gives it potential value after Heavy Bombers come.
The Medium Bomber is unreachable by land and sea units, but doesn't block attacks on other units on the same tile. This unit has Stack-Escape.
MP2-Avant-garde: Medium Bomber now available with Advanced Flight, improved to A7, 15 moves.
==15. Bombers updated==
A:12 D:3 M:16 FP:2   Fuel: 2 turns. Cost: 120 shields. C:1 Renamed “Heavy Bomber” to distinguish it from the Medium Bomber.  This is now a useful unit due to deprecation of the OA-flag. Defense is raised to 3. This represents the Heavy Bomber's mass and multiple gunner stations. An undamaged Heavy Bomber now has a hope to defend against a Fighter (24% instead of 1%). 
The Heavy Bomber is the first air unit that can carry a Bomb.
The Heavy Bomber is unreachable by land and sea units but doesn't block attacks on other units on the same tile. This unit has Stack-Escape.
MP2-Avant-garde: Heavy Bomber is now available with Radar tech.
== 15a. Strategic Bomber added ==
A13: D:4 M:16 FP:2 Fuel: 3 turns. Cost 135 shields. C:2 The game had 38 units in the first half of the tech tree and 21 in the latter half. Yet the latter half is when the "Grand Finale" takes place. Adding late game units smooths balance, closes gaps, and creates more diversity in tactics. Available with Rocketry.
Effect: A small increase to attack strength and an extra turn of fuel allows deeper strikes and more coordinated tactical uses. High maximum altitude and gunner stations give it even odds against attacks from Fighters.
This unit can carry two Bombs.
The Strategic Bomber is unreachable by land and sea units but doesn't block attacks on other units on the same tile. This unit has Stack-Escape.
==16. Anti-aircraft Artillery added==
A:2 D:2 M:2 FP:2. 2x attack/defence vs "Air". Cost: 50 shields. Is able to attack air units.
Explanation: There are now many more air units. That's great, but made pre-existing flaws more obvious:  1) There were no air defenses until Rocketry, 2) Air defenses were unmovable. 3) Unreachability was the only way to represent Air cover, but allowed unreal exploits which had no counters.
The AAA is 2FP and A:4 D:4 vs Air. It requires anticipation of where your enemy will strike. This is exactly how real AAA were deployed, with moderate effectiveness.  AAA provides movable air defense, and a patch to some Unreachable exploits. Its cost/attrition ratio mildly counterbalance mindless Fighter-spam strategies.
Effect:   You can make an AAA that's usually less effective than 50 shields spent on other units. It gives a slight edge in some situations, and helps resist Air-only strategies. Balance is restored to air/land relationships. AAA qualify as weaponry for Marines and have the same abilities: they can be transported on any unit that carries Marines, can attack from or to non-native tiles, and do not lose a turn when unloading.
Transported AAA can defend their tile on both Land and Sea.
AAA cannot attack Submarines, Missiles, or Jet Bombers.
MP2-Avant-garde: AAA now gains the "TransportDefender" flag: able to defend while transported, even on ocean tiles.
== 16a. Mobile SAM added ==
A:2 D:2 M:6 FP:2. 2x attack/defence vs "Air". Cost: 75 shields. Is able to attack air units.
This unit is the logical upgrade for the AAA in the ultra-late game, allowing air defense to keep up with newer air units. It has the same stats but 30hp instead of 20hp. It also has improved movement and the ability to carry one missile. The AAA still remains relevant for special ops because of its transportability and non-native attack capabilities. Because of this, the standard upgrade path is disabled in order to avoid unintentional upgrade of an AAA engaged in special ops. An AAA that has been in service for 10 turns can be converted in the capital city to a Mobile SAM, if one possesses the tech Space Flight. Conversion time is 4 turns.
== 17. Air units can airlift themselves ==
They don't need to "fit" in an airplane. They are airplanes. This fixes a ridiculous irony. Land units could move across the world and arrive at battlefronts faster than aircraft, because they were airlifted by aircraft (?!).
== 18. Balloon added ==
A:0 D:0 M:5 Fuel: 2 turns. Cost:25. Upkeep:0. This was added because 1) Chemistry gave nothing, 2) Play-testing revealed it was a lot of fun. The Balloon is a unit with excellent vision. It can float for one extra turn before it must return to "refuel" at a City, Fortress, or Airbase; or on larger ships with a cargo capacity of 4 or higher, such as a Carrier. The Balloon is unreachable by primitive units. From Riflemen and Ironclad onward, it can be shot down. Balloons cannot cross mountains.
The Balloon is a unit that can play peek-a-boo over borders to collect intel. This "harmless" little unit does a lot to arouse the four i's: incidents in diplomacy, intrigue, interactions, and intel. Balloons were effective units for collecting tactical intel, but only before firearms gained greater range and accuracy. This is a realistic unit but usually will not have a major influence on the game. It might increase intrigue, tactics, player interaction, and fun.
The Balloon is unreachable by primitive land and sea units but doesn't block attacks on other units on the same tile.
== 19. Jet Fighter added ==
A:6 D:5 FP:2 M:24 Fuel:1 turn. Cost:70. The gap between World War II era Fighters and Stealth Fighters upset playable balance in Air/Land/Sea relations.  It wasn't realistic either.  The Jet Fighter fills the gap between Fighters and Stealth Fighters and restores balance: it adjusts for Fighters having no upgrades for too long, and more units which can counter them. More than just a step on the way to Stealth, the Jet Fighter's cost/defense ratio keeps it tactically relevant in the final end game.  Requires Avionics.
Like all Fighter-types in all MP rulesets, the Jet Fighter prevents land and sea units from attacking the tile it is on. This unit has Stack-Escape.
MP2-Avant-garde: Jet Fighters now available with Avionics.
MP2-Avant-garde: All fighter-types can now do the new Vigil command.
== 20. Jet Bomber added ==
A:15 D:1 FP:2 M:19 Fuel: 3 turns. Cost:145. An unrealistic gap existed between World War II and Stealth Bombers. Jet Bombers' role is long range saturation bombing. This unit can "carpet bomb" –  it can pillage tiles. The trade-off is high cost and low defense. The Jet Bomber also provides a possible response to fortified positions, Paratrooper incursions, and so on. Requires Space Flight.
This unit can carry three Bombs.
The Jet Bomber flies at stratospheric altitude and is not reachable by AAA or propeller-based primitive Fighters. The Jet Bomber is unreachable by most land and sea units, but doesn't block attacks on other units on the same tile. This unit has Stack-Escape.
== 21. Stealth Aircraft improved ==
Stealth Bomber: A:19 D:5 FP:2 M:24 Fuel: 2 turns. Cost:160. The very last and premier offensive unit was underpowered relative to earlier units and late game defences. The Stealth Bomber gains +1 to attack, making it 5% stronger than the cheaper earlier Howitzer. SAM Batteries go from 2x defense to 1.25x defense against the Stealth Bomber. Against a city with a SAM Battery, the Stealth Bomber is 20% weaker than the Howitzer, instead of half strength. Likewise, Stealth evasion abilities give it a compensatory 25% bonus against units with an Anti-Air bonus. It is capable of carrying 2 Bomb units as cargo. The Stealth Bomber is unreachable by most land and sea units, but doesn't block attacks on other units on the same tile.
Stealth Fighter: A:8 D:4 FP:2 M:28 Fuel: 1 turn. Cost: 80. Although the Stealth Fighter gets no changes to basic stats, it gets improved viability against SAM Batteries. SAM Battery bonus against Stealth Fighters goes from 2x to 1.25x. Stealth evasion abilities give it a compensatory 25% bonus against units with an Anti-Air bonus. This better represents the unit's stealth capability. Like all Fighter-types in all MP rulesets, the Stealth Fighter prevents land and sea units from attacking the tile it is on.
These units have Stack-Escape.
MP2-Avant-garde: All fighter-types can now do the new Vigil command.
MP2-Brava: Spy Plane now upgrades AWACS with Stealth technology.
== 22. Spy cost changed ==
Cost: 35. There were complaints that spies were OP. But keeping true to MP DNA, spies have the same abilities (and more!). When other upgraded units are increasing in cost by 10 or 20, a small +5 increase to cost is a gentle nudge toward a better balanced game, without radically altering it. This has almost zero effect on a player making an occasional spy, but a more significant 15% penalty on massive overproduction of spies.
== IV. Project Poseidon: Glorifying the Ancient Seas ==
Introduction: The early sea game was bad. Out of ~35 early game units, there were only two sea units! With only two units, you'd think they'd be versatile and multipurpose, but they weren't. The A1 D1 Trireme was like a Warrior at 4x cost. It required diverting bulbs from more important techs. Nations acquired feudal units before the first ship hit the seas! Meanwhile, someone eliminated original game mechanics: the possibility of exploration/colonization, and the Trireme's ability to cross seas with a bit of risk. No problem, just get the next sea unit, right? The Caravel at A2 D1 was like Horsemen at 2x cost, but needed an investment of 1000 bulbs. Any ship you made was D1—40 shields down the toilet if spotted. The result is well-known. The ancient sea was not featured in the game.
Project Poseidon makes the ancient seas a lot better, with the adventure of ancient seafaring nations. New sea units model the balance in ancient land units. Mostly, the new units: a) are historically realistic, b) expand diversity of strategies, c) increase playability/balance. An important goal is to not make ancient sea strategies obligatory.
==Combat Rounds==
In ancient times, a nation can struggle to field an army. If a nation made a ship, it was only a token one or two. It was a costly investment that could be lost on a flip of the coin. Freeciv server's new combat rounds feature provides a balance for this. Ancient ships have 15 combat rounds. When a ship initiates an attack, there are 15 rounds of combat (15 hit points lost.) Both units might survive. Survival odds for ships improves. This adds tactical depth. Two ships on a tile have good chances to survive two attacks, each absorbing damage to protect each other. Attacking ships working in numbers can engage in a real ancient tactic: tandem attacks. One ship initiates battle to degrade the target, and the second finishes it off. The combination of these elements brings the ancient seas to life, and simulates the feel and flair of ancient sea battles. And it showcases a new Freeciv server feature.     
Effect: Before, there was a flat 50/50 risk on two triremes in a battle, with one nation losing 40 shields on the flip of a coin. This is replaced with a much better dynamic. Both units might survive, but be damaged with slower movement. This gives the edge to the nation with tactical support from other ships OR being closer to a friendly city it can escape to: both realistic elements. Combat_rounds mean that stacking ships could have a cascading effect: each surviving ship defends the whole stack. This is balanced by increased risk for larger stacks: one of the battles may end in a killstack. This creates interesting and realistic dynamics for both tandem attacks and tandem defense. Now tactics determine game results instead of a mindless coin flip causing a game-deciding shift in balance of power.     
== River-worthy ships ==
Ancient ships can travel rivers and attack on rivers. Cities adjacent to a river can make river-ships.
Explanation:  Formerly, Freeciv server couldn't let ships travel rivers. MP was never updated after the feature was added. The new feature helps with an issue: Freeciv Map Generator creates continental maps with unconnected lakes and seas, preventing games with significant land AND naval action.     
(Which ships could travel rivers was often hotly debated on topics like the average depth of a Freeciv river. The answer is: "deep enough to increase trade, therefore deep enough for the wooden ships that historically used rivers."
Effect:  Seven of the eight ancient ships can travel by river. This is one of several ways that MP2 re-balances the Map Generator's tendency to make isolated and unconnected water. River access was extremely important in ancient civilization. A nation that puts no defense on the entrance to its rivers is asking for trouble! If you don't place a city there, fortify a unit on your river to secure it, then make a Fort or Fortress. Use rivers to your advantage.
IMPORTANT NOTE: Older versions of Freeciv had a flaw with "double moves" which were exploitive and OP for river ships, trains, trucks, or anything else transporting land units over land tiles. This is why all such units had been removed from older mainstream rulesets. However, Freeciv-Web has the new server options universal_unload and unload_override. The ruleset's defaults for these values are conservative and work well. Use /help option_name for more info.
== The Ancient Ships ==
changes to MP1 are in red
	Ship 	Cost	A	D	M	Hp	Combat
Rounds	Cargo	Trade	Shore Attack	
Tech Req. / Notes
	Boat 	10 	0	1	4	10	15	1 	✓ 	✗ 	NONE /
Trade tech not needed
	Trireme 	20 	1	1	6	10	15	2 	✓ 	✗ 	ALPHABET / 1turn@sea
	Longboat 	25 	2	1	6	10	15	1 	✗ 	✓ 	MAPMAKING
	Galley 	30 	2	2	6	10	15	2 	✓ 	✗ 	SEAFARING
	War Galley	40 	3	3	6	10	15	3 	✗ 	✓ 	ASTRONOMY
	Ram Ship 	35 	4	2	6	10	
∞	0 	✗ 	✗ 	ENGINEERING / bad vision / no rivers
	Caravel 	40 	4	4	7	10	15	3 	✓ * 	✓ 	NAVIGATION *can't build Wonders
	Galleon 	40 	2	3	8	20	15	4 	✗ 	✓ 	MAGNETISM
	Frigate 	50 	4	3	8	20	∞ 	2 	✗ 	✓ 	MAGNETISM
Boat. A Boat can travel rivers and oceans, but it must always stay near shore. It can carry one unit. Boats can do primitive commerce: they can establish Trade Routes without Trade tech. Early Trade Routes represent primitive bartering which generates little trade. In some cases, it could help a nation advance faster, or enable future good relations with neighbors. To build Wonders with Boats. This may help finish a first Wonder earlier.
Trireme. The Trireme gets important fixes to spark adventure at sea: a) It's not overpriced, b) It can use rivers, c) It regains its original ability to travel in Deep Ocean. d) It may only spend one full turn in "open waters" that don't touch a coast. On the second turn-change that a Trireme is in open waters, it will be lost at sea. e) Each time it ends a turn in a city or adjacent to coast, it "refuels" and can spend the next turn in open waters again, f) Trireme is now a "Commerce Unit"—true to history, it may build Wonders, Enter Marketplaces, and establish Trade Routes. Note: Commerce functions require that you have the Trade tech. ☀ Now the early seas come to life: a player makes a Trireme to build a Wonder, but first explores the sea and meets other nations' Triremes. Life at sea is awakened!Longboat. The Longboat is the first naval unit with an offensive role. It can bring one land unit to shore.
Galley. The Galley is the all-purpose sea unit of ancient times. It is also a Commerce unit.War Galley. The War Galley is the premier warship of ancient times. Its combat strength and cargo capacity are a real threat. However, it has a high cost and lacks commerce ability.Ram Ship. The Ram Ship is an offensive ship with only one purpose: destroying other ships. It has poor vision, no transport or commerce ability, and may not travel on rivers. But there will always be a winner and a loser when a Ram Ship attacks. Strategically, Ram Ships make great counterstrike defense for nations not invested into sea techs.  
Caravel. The Caravel is a major advance in combat, speed, range, and transport capability. It replaces many ancient sea units. Caravels provide most of the commerce abilities of the earlier Galley, but cannot build Wonders.Galleon. This unit is repurposed to balance the transition between ancient and modern sea units. The reasons:  a) Make the Galleon actually be a Galleon, (comparable to a weaker frigate but with a defensive bias.) b) Don't penalize Caravels when they "upgrade." c) Offer more diverse strategies. When they attack, 15 hit points are lost between both units before combat ends. But in the Galleon's case, it's a 20hp unit. This curtails its gains in combat strength, but also gives it suitability for survival. It is the only unit to have the combat_rounds of earlier ships and the Stack-Escape feature of the more modern ships.Frigate. The Frigate stands with one foot in ancient times and one foot in the modern era. Like other ancient ships, it can still travel rivers and transport units, but is closer to modern ships in that it has 20hp and unlimited combat rounds. This makes it quite versatile. The Frigate and all more modern ships feature Stack-Escape.  
== V. Project Neptune: Modern Naval Re-balance ==
== 1. CanEscape ==
Stack-Escape: Modern Sea (and Air) units have a chance to escape Killstack when the stack defender dies.
Explanation:  Killstack created unrealistic scenarios in naval warfare, utterly breaking it.  In reality, fleets on open waters enjoy strength in numbers.  A single ship attacking an expensive mega-fleet should not be able to kill the entire fleet–especially since one attacker can't chase a fleet escaping in all directions. A causal chain led to bad results: Huge cost of lost stacks → Fear of stacking ships → Lack of fleet co-defense → High priced ships were easy victims → Game degenerated into spamming cheap Submarines & Fighters → Naval warfare was ruined. 
Effect: Killstack is still in effect, but diminished. When the "stack defender" is defeated, each unit in a “defeated stack” has a 50% chance to escape the Killstack if it has more moves remaining than the attacker. This causes interesting results:  a) Ships are likely to have a 50% chance to escape Killstack if they are attacked before they moved, b) Ships attacked by Air units coming from nearby will probably not avoid Killstack, c) Ships or subs who "lie in wait" in their home waters can surprise or "ambush" and likely get a Killstack.
Fleet movement becomes a new tactical consideration: cat-and-mouse games and other tactical maneuvers. Modern Naval Warfare enters the game at a higher level. This feature applies to ships more advanced than the Caravel.
== 2. Modern Naval Re-balance ==
Introduction:  A huge mistake in sea balance existed. The Submarine was much stronger than original Civ I/II. This caused massive imbalance. The Sub had the same attack strength as a Battleship at ⅓ the cost and earlier in the tech tree. This eliminated rational use of other surface ships. This could be fixed by restoring the Sub back to original strength (MP+), or by introducing ASW capability from other ruleset re-balances. The latter was chosen as it keeps two positive outcomes instead of only one. The changes below are documented in all manuals.
Changes to the modern fleet:
Items in Red show changes from MP1:
unit 	A 	D 	FP	HP	M 	Cost	Carry 	Defence Bonus 	Tech
Submarine 	12	2 	2 	28	10	50 	8 missiles	Unreachable by Air	
Automobile
Destroyer 	5 	5 	1 	30	12	60 	 	4x:Subs 	Electricity
Cruiser 	6 	6 	2 	30	11	80 	 	2x:Subs 	Steel
Battleship 	12	12	2 	40	10	160 	 	2x:Subs 	Refining
Aegis Cruiser 	8 	8 	2 	30	11	100 	2 missiles	2x:Subs, 3x:Air 	Rocketry
Missile Destroyer	5 	5 	2 	30	12	60 	1 missile 	2x:Subs, 2x:Air 	Rocketry
Cargo Ship 	0 	1 	1 	30	7 	45 	4 land 	 	Industrialization
A Naval Rebalance Odds Chart is also below.
Submarine. A12 D2 FP2 HP28 M10. This unit was balanced in Civ I/II with a lower attack strength, but MP2 keeps the higher attack strength because it gives Submarines realistic hit-and-run-away capability against weaker ships. The huge excess over original strength is balanced another way: stronger warships get ASW bonuses. This solves the OP issues. But there was an underpowered issue also. Air units were OP at destroying Subs. The Submarine's ability to submerge to avoid attack had been totally ignored. In MP2, Submarines are now unreachable and immune from air attack, but can't stop Air units from attacking other ships on the same tile. MP1 & MP2 Subs compare as follows: The MP1 Submarine was a wildly OP offensive unit that cost less than every other sea unit but was able to slaughter every sea unit regardless of cost, strength, or higher tech level. But it had an equally fatal flaw: after any attack, it was guaranteed to be found and killed by any Air unit in range. In spite of the fact that Destroyers should be the unit that Subs fear most, Destroyers were 0% effective in defending and only 48% effective in attacking (x̄=24%). In comparison, MP2 Submarines are cheap and strong offensive units with a cost-attrition advantage on surface ships, but may need numbers to achieve it: wolf-pack tactics. The loss of wild OP offensive strength is compensated with the capability to submerge to avoid all Air attacks. The Submarine's new nemesis is now the Destroyer, which is 35% effective in defending and 80% effective at attacking (x̄=57%).
Destroyer. A5 D5 FP1 HP30 M12. +1 strength. 4X ASW defense. This is the second of two steps to fix a hole in naval balance. Formerly, unit evolution was: Ironclad A4 D4 FP1 >> Destroyer A4 D4 FP1 >> Cruiser A6 D6 FP2. The Destroyer is supposed to be: 1) an upgraded choice between Ironclad and Cruiser,  2) a cheaper support ship for Cruisers, Battleships, Carriers, 3) an anti-submarine unit. Its role is to scout, patrol and destroy. But, this "Sub-hunter” only had a 48% chance to sink the cheaper Sub it's supposed to hunt, and a 100% chance of defeat against a Sub attack. Giving the Destroyer FP2 would be an easy fix, but that is OP at the stage the Destroyer enters the game. The solution is to give the Destroyer a mini-buff to A5 D5 and upgrade it later. Now the Destroyer has an 80% chance of success when attacking a Submarine, up from 48%. Its chance of defending against a Submarine goes from 0% to 35%. Now, each is likely to kill the other when attacking. This creates realistic "cat-and-mouse games" between Subs & Destroyers. Finally, Freeciv gets proper naval warfare!
Cruiser. A6 D6 FP2 HP30 M11. 2x ASW defense to balance the Sub's hit-and-run buff. Odds of a Sub successfully attacking the more expensive Cruiser go from 97% to 43%. This represents an economic value:odds ratio in favour of Submarines:  2 Subs vs 1 Cruiser yields an expected 28.5 shields lost for 80 killed. (MP1 attrition ratio was 1.5/80.) Besides being closer to the original odds, the defense bonus is further justified when one considers that Surface ships can no longer rely on Fighters for easy Sub kills.
AEGIS Cruiser. A8 D8 FP2 HP30 M11. 2x ASW bonus. Even with the 2x bonus, the cheaper older-tech Submarine still has good value economics: two will sink an AEGIS Cruiser, exchanging 50 shields of old tech to sink 100 shields of new tech. Submarine strategists accustomed to the old imbalance should consider “wolf-pack tactics.” 3x defense against Air Attackers replaces the old 5x (it now requires 8 Fighters to sink an AEGIS instead of 14.) The AEGIS gets compensation for its change to 3x AA defense. It can now attack Air and Missile units directly. A counter to the exploit of "fighter hovering" over sea units is a major benefit to playability/balance. The AEGIS is a missile cruiser, so it gets another realistic ability: it can now carry 2 Cruise Missiles. The final result is increased realism, viability, and more playable balance for surface ships. An OP anti-air bonus is nerfed but remains very strong, while small buffs compensate that and improve balance and playability.
Battleship. A12 D12 FP2 HP40 M10. 2x ASW bonus. Three Submarines have a 65% chance of sinking the 160 shield Battleship, instead of 2 Submarines having an 84% chance. This deserves careful analysis for mathematical balance:  The correction gives a 65% chance of losing 100 shields to sink 160 shields, instead of an 84% chance of losing 50 shields to sink 160 shields. Attrition ratio goes from game-breaking to a more realistic 1.39x in favour of the Submarine, closer to original Civ I/II. The Battleship is now available with Refining and can emulate the brief heyday it had in real history. This is the only warship with no upgrade, but there always remains a use for a D12 FP2 HP40 unit.
Carrier. A1 D9 FP2 HP40 M10. The Carrier has no change other than to its cargo classes. Besides the usual aircraft and missiles, it can transport Balloons, AAA, and Marines.
MP2-Avant-garde: Cost reduced to 155 (was 160), carry capacity increased to 9 (was 8.)
Movement point ratios tuned to use the refined accuracy that 2x move rates offer. A Battleship is just barely slower than a Cruiser. But because 1x units can't be set to partial movement points, original Civ was forced to exaggerate the difference with a whole move point. The evolution to 2x moves then doubled this already exaggerated difference. Ironically, a solution is built into 2x moves, as it creates a doubled scale that can tune units with "half moves." This is great for fixing units with lop-sided movement ratios. Battleship:Cruiser:Destroyer ratios now change from 4:5:6 (1x) to 10:11:12 (2x). This yields the same difference in tile range and now gives almost the exact ratios for real life speeds. 2x move rates are flipped from a downgrade into an upgrade which benefits balance and playability.
Starting with Ironclads, warships can pillage buoys.  Letting warships pillage buoys is realistic and more playable. Be careful! Your opponent will see you doing it!  A new component of realism, guessing, daring and danger!
===Naval Re-balance Odds Chart===
.
== 3. Missile Destroyer added ==
thumbA:5 D:5 HP:30 FP:2 M:12 Cost:60  2x defense vs Subs & Air units. C:1 Cruise Missile.  
Explanation: This unit upgrades the Destroyer after Rocketry is known. A flaw in sea unit upgrade progression had made the Destroyer identical in strength to the earlier Ironclad. This left a gaping hole: from mid-game on, there were no "medium strength" surface ships. In theory, giving the Destroyer FP:2 would have filled the gap with a ship exactly in between the strength of Ironclad and Cruiser. The Destroyer could then properly fulfill its tactical roles and missions well into the late game. Two things worked against that choice: 1) At the phase of the game when the Destroyer enters, FP:2 would be OP, 2) The little-used Cruiser would be used even less.   
The solution was to give the first Destroyer a mini-buff over Ironclad for mid-game relevance, then make it upgrade to the Missile Destroyer in the late game. This has five benefits: a) realism, b) finer tuning of naval balance, c) better playability, d) it mirrors the upgrade path for Cruisers, e) the upgraded unit has continued relevance until the end of the game – during a period when Destroyers are the most commonly used surface ship in real navies.
Effect: Perfect naval balance. The Destroyer is now able to continue its support roles of scouting, seek-and-destroy, and also the duties of regional patrolling and "incident police."  
== 4. Cargo Ship added ==
A:0 D:1 HP:30 FP:1 M:7 Cost:60 C:4  
Explanation: The addition of river travel and maritime commerce units requires a modern unit that is representative of these game features. The Cargo ship is a commerce unit that can travel on rivers and continue maritime commerce abilities of earlier ships. Its ability to transport units could be used logistically, diplomatically, economically, or militarily.
Effect: The expanded depth of commerce and river travel can continue in the latter half of the game.
== 5. min_speed Adjustment ==
From Ironclad onward, min_speed of damaged ships is 3 (was 2.)
Explanation: MP's change to 2x move rates mistakenly left the min_speed of ships at 1x rates. Ships became relatively less effective. Since 2x allows finer tuning than 1x, min_speed can be upgraded to have proportionality.
Effect: min_speed becomes roughly ⅓ of total speed. From Ironclad onward, min_speed is 3 moves. Older ships stay at 1x rates; modern ships get 1.5x. This "conservatism" is compensated in other ways (see below.)
== 6. Crew Repair Bonus ==
Sea units have crews which pro-actively repair damage regardless of movement.
Explanation: Crews repair their ships, but this was unrepresented in-game. Ships had the worst healing traits of any unit. Often, ships were "disposable use", unable to re-enter action for centuries. Realism, playability, and balance suffered. The imbalance was made worse by: a) farther distance from cities, b) less or no bases to heal in, c) greater rarity of Port Facilities, d) lack of Fortify-healing, e) Gibraltar Fortress, f) min_speed causing slower arrival to distant healing locations. Combined, these six forces created the "Red Mage phenomenon": when preserving the potential to use a unit is more valuable than actually using it. The new server feature Unit_Recover_Pct lets MP2 fix this.
Effect: Sea units get "crew repair" applied every turn. The effect is 8% of total hitpoints (rounded down):
Crew Repair	Crew Repair
Ship type: 	Repair rate:
10hp 	0hp
20hp 	1hp
30hp 	2hp
40hp 	3hp
Note: 10hp ships are unaffected by the min_speed and Crew Repair upgrades. In MP2, these ships are cheaper, available earlier, and have higher survival rates from combat_rounds.
==VI. Improvements and Wonders==
==1. Pyramid gains its Classic effect==
Food storage +25% in every city added to existing effect of Rapture in its home city. Req: Masonry.
Explanation:  Making the Pyramid rapture the city who owns it was an attempt to lessen the gap between rapture and non-rapture governments. But it turned out to be overpriced and even less effective than the originally underpowered effect. Combining both effects gets closer to the desired result. 
Effect:  Adding the Pyramid's original effect restores balance to non-rapture nations.  It may provide a “vertical alternative” for cramped nations who can't expand territorially.  In the early game, for roughly the cost of 4 Granaries, you get a “half Granary” in all cities.   
For late-game non-rapture governments, this Wonder can be thought of as a “viability patch.” The Pyramid is not meant to give equality to all governments, and you are cautioned that it doesn't. It corrects a “widening of the gap” that MP1 unintentionally aggravated. It will allow more flexibility in strategies and more flexible timing of revolutions. 
Also see: Non-Representative Governments in MP2. 
==2. Copernicus Observatory reduced to 100 shields==
Explanation:  This Wonder was meant to enable early science. It was the same as a Library at 3.3x the cost. An early science strategy was 333% better off by buying 3 more Libraries, pocketing 20 shields, and skipping Astronomy. There was no incentive to get Astronomy and Copernicus.  
Effect:  Copernicus now costs 1.7x more than a Library with the same effect as one.  Is it now conceivable to risk sacrificing other early techs and push for early Astronomy and Copernicus?    
==3. Great Wall improved==
Cost 275, obsolete when any player gets Machine Tools. Req: Masonry.
With the more rapid pace of Multiplayer games, the Great Wall was undesirable because of accelerated obsolescence. By the time it was affordable, it was almost obsolete. Now the Great Wall is something to consider if you have more than 6 cities on a long border with Genghis Khan as your neighbor. Obsolescence by any other player getting Machine Tools helps limit extended strategies to exploit it, and introduces external forces and timing and risks for extended use of the Wonder.
MP2 Avant-Garde: the Great Wall does not take effect until a city has been founded for at least three turns. In addition, its population must be less than one fifth foreign (i.e., a newly conquered city doesn't instantly grow walls.)
== 3a. Great Library renamed to Supreme Court ==
Cost 200, obsolete by: None. Req: Literacy.
This is essentially a rename and it mostly acts like an extra Courthouse in every city. However, note that Courthouses are quite modified now. With respect to corruption, incite protection, upkeep, and other bonuses, the Supreme Court gives the same effect as an extra Courthouse in all your cities. By itself, it gives no bonus against hostile diplomatic acts. However, owning the Supreme Court enables each city to build a Homeland Security building to acquire those additional bonuses. This Wonder is never obsolete.
=== Homeland Security ===
Cost 30: upkeep 0. Requires: Supreme Court. Cannot be sabotaged.
A city can build Homeland Security if you own the Supreme Court. Homeland Security gives the same bonus as a Courthouse vs. all hostile diplomatic acts. This patch to make an "extension" of the Supreme Court had 3 reasons:
* The cost of Supreme Court had to be low to diversify the early game strategies for which it was intended.
* Late game diplomat protection for 200 shields was too "cheap and easy", making a bit of a "Golden Path."
* Currently, Freeciv server has consistency issues with determining if a target/victim owns a Wonder.
==4. Wonders restored to full nationwide effect==
No longer “on the same continent”.
Explanation:  Prior to Multiplayer, Great Wonders were overpowered for a game with >20 players. Great Wonders were made into “even Smaller Wonders” – working only on the same continent. This broke Wonders on some maps. 
Effect:  No effect on most maps. On islands maps, Wonders will no longer be useless. On multi-continent maps, this eliminates game-breaking disadvantages for getting placed on off-shore islands or smaller continents.  
==5. Courthouse reworked and fixed==
Explanation:  In MP1, most players never built Courthouses. Bad rounding formulas reduced corruption by an average of only 41%.  In Democracy, +1 content citizen was poor value compared to the Amphitheater. Also, MP1 rules removed Incite Revolt, nullifying the main benefit of the building, yet keeping the same inflated cost. The result was a broken Courthouse. The new Courthouse keeps true to the spirit of the building: to provide safety, stability, law and order, and benefits against hostile diplomacy:  
*Cost reduced to 45.  
*Corruption reduction fixed — after rounding, the average is now 53% reduction.
*Eliminates “tile corruption” penalties during Despotism and Anarchy.
*+1 free unit upkeep from "greater law and order."
*Anti-Espionage: Protects your diplomatic units against hostile diplomatic units by roughly 15% (30% off the average base chance of 50%), lowering success chance to 35% (prior to other modifications.) Protects your city from the basic 'Steal Tech' action by 35%, lowering base success to 45%. Increases protection from all other hostile diplomatic actions by 20%.
Effect:  It now reduces corruption by ½ instead of ⅖, a big help for non-Democracy governments. Since preventing revolt was half the Courthouse's value, the building gets substitute compensations: +1 free unit upkeep. The removal of “tile corruption” means that in theory, this could provide the possibility for a Republic to revert to a temporary war-time Despotism. Re-introduces the Courthouse's original intent for protecting against diplomatic actions. The new Courthouse helps restore the strategic menu of options that original MP1 accidentally removed. 
This change provides a small balance improvement to governments who suffer corruption, though the cost of reducing that corruption is steep, and break-even is many turns out.
MP2-Caravel: The +1 content bonus for Democracy now applies to all governments, for better game balance.
==6. Granary costs 35 shields==
Explanation:  The Granary is a vehicle for growth in non-rapture governments.  Non-rapture governments were underpowered from what they should be. This improves game balance between governments.
Effect:  Another small adjustment for non-rapture governments. Also see: Non-Representative Governments in MP2.  
==7. Mass Transit==
Costs 60 shields and increases base trade by +2.
Explanation:  It's unfortunate that Mass Transit was utterly broken.  It was the cost of 3 Engineers with upkeep equivalent to 2 Engineers. It reduced the effect of Population Pollution (not Production Pollution).  Let's compare that to 1 Engineer.  A single Engineer can clean pollution that came from Population OR Production in any nearby city. Mass Transit might prevent pollution in a single city if it came from Population (but it usually comes from Production.) When Pollution doesn't happen on a given turn, an Engineer can still irrigate, road, rail, make a fort, scout a border, etc. Engineers were ridiculously superior to Mass Transit. Too many Engineers ran around cleaning pollution while pollution prevention was never purchased. A major fix was needed. The ROI of the improvement is now positive. Realism is increased:  Mass Transit increases mobility of citizens and generates small revenues from tickets.  The Engineer is cheaper and has all the other benefits, so it remains a strong alternative: no classic strategies get broken. But the nation who goes for Mass Transit enjoys:  a) +2 trade to recoup the extra 20 shield cost over an Engineer;  b) Pollution control becomes preventative; c) Increased playability.
Effect:  Very little.  Overall play remains the same. You can choose to pay a little more than it's worth to have less annoyance cleaning pollution tiles, exercise preventative control rather than reactive control, and slowly get a return on investment that's tiny compared to other investments.
==7b. Recycling Center==
Costs 70, upkeep 1, increases base production by +2.
Explanation:  Recycling Center was also broken. Recycling generates raw recycled materials which aid production. Therefore, this improvement slowly pays for itself by adding +2 shields to the city's base output. A useless improvement now becomes a modest investment that increases playability. 
Effect:  Very little. The game remains the same, except some people might use this improvement. 
== 7c. Police Station ==
* Costs 50, upkeep 2. Prevents two unhappy citizens caused by military activity. 
* Gives 10% bonus against the basic "Steal Tech" action.
* Gives roughly 10% bonus against diplomatic combat (20% off average base chance of 50%)
* Prevents enemies from establishing an embassy without first agreeing to cease-fire, armistice, or peace.
* Gives +1 veteran level to Spies and Diplomats.
Explanation:  The Police Station was handicapped. Women's Suffrage made it superfluous. Now it gets a new ability that Women's Suffrage does not give: a 10% bonus against hostile diplomatic combat and tech theft; and the ability to selectively prevent "hostile" embassies intended only for espionage. Nations were unable to impose extra measures to combat espionage in cities they knew to be targets. While the new Courthouse is the major fix for that, the Police Station allows amplifying protection by another 10% and gives an extra bonus against hostile embassies.  
==8. Palace==
Makes +1 Happy in Capital City.
Effect:  Capitals are typically larger than other cities, and representative of national pride, wealth, and morale. Because of capital production bonuses, these cities often used tiles with less luxury, so couldn't grow as large. Now, under non-representative government, it's more feasible to unlock celebration bonuses in the capital city.
Note: MP1 has an undocumented error: Courthouses were useless in cities with a Palace. This was also fixed.
==9. Hanging Garden==
Gives +2 luxury to its home city. Remains the same in all other ways.
Explanation:  Civ2civ3 made Hanging Gardens have more effect in the home city. Selecting a city to host the Wonder is now strategic. Your most corrupt city that needs help to celebrate? A coal city needs more luxury? Your border city from which you want to send aggressive units? Since this creates greater depth of strategy, this change was imported into MP2.  
Effect:  The city chosen for Hanging Gardens becomes a small strategic component.
MP2-Caravel: Hanging Gardens now becomes obsolete by Steam Engine, not Railroad. This increases the attractiveness of other strategic Wonder paths as well as providing further encouragement to acquire Frigates before Ironclads.
==10. Colossus expires with Automobile==
Explanation:  This change is common in other rulesets: Superhighways provide a replacement for a city that may be dependent on Colossus to support its size or other functions.
Effect: Colossus enthusiasts are happier.
==11. Lighthouse==
Improved and adjusted. +2 move, +1 vision, obsolete: Miniaturization. Cost: 170. Req: Map Making.
Explanation:  Lighthouse was OP in Classic rules. 200 shields gave ships +1 move and +1 vet. MP1 overcorrected: it removed the vet bonus, accelerated pace to go obsolete sooner, but kept the same cost. 2x moves came to MP1 without 2x for Lighthouse. The most valuable bonus was eliminated, the secondary bonus became half strength, the cost remained the same, and it expired much sooner. Thought was needed to resurrect this Wonder. With only ¼ of its original value intact, a balanced cost would make it too cheap and thus too common. The solution reduces cost to 170, corrects the bonus to 2x move rates, delays the expiration, and gives +1 vision to replace the loss of +1 vet. Obsolete by:  Miniaturization.
== 11a. Adam Smith's Trading Company ==
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Cost: 300. Wonder remains the same, but now enables 3 new types of specialists. Req: Economics.
Explanation:  The ability to create new specialists has been in Freeciv server for a while. Since custom specialists have become a tradition in newer versions of the commercial series, MP2 showcases this "new" feature by importing three new specialists. To avoid game-wide balance change, they are activated only by a wonder, and the three new specialists are generally of equal or lower value than the standard three. However, they can provide an interesting twist by giving an economist player more control over flexibly tuning outputs.
 Each Laborer produces +1 production per turn. That is, the same output as a blank 0/1/0 mountain tile. Each Farmer enhances food output by +1 food, the same as using a blank hill or swamp tile, 1/0/0. Each Merchant generates +2 trade and +1 gold, prior to bonuses from Buildings or Wonders.
Effect: From one perspective, players can safely ignore three new specialists who are equal or lower in worth than the standard three, with no substantial change to game dynamics. From another perspective, the Adam Smith wonder embodies Adam Smith's theory that the value of an output is relative to the need. For example, using a Laborer when 1 more shield will finish a unit, or using a Farmer when there is a shortage of food. This gives micro-improvement to a wonder that was considered slightly less valuable than other wonders.
===== NOTE: The Freeciv-web client has user interface shortcuts for specialists. Shift-Click changes all specialists of the clicked type. To bypass secondary specialists and only cycle through the three primary, click with Ctrl or Alt or ⌘) =====
== 11b. Michelangelo's Chapel ==
Cost: 300. Also confers a bonus to existing Cathedrals: +1 happy, +1 forced content. 
Explanation:  When this became a small wonder, a side effect was that the original Cathedral became almost extinct. An evolutionary step restores the Cathedral back to having a place in the game.
Effect: In cities with a Cathedral, it will enhance the Cathedral, adding the effect of +1 happy +1 forced content, stacked on top of the original effect. In all cities without a Cathedral, it behaves as before — it makes all cities get the effect of a Cathedral. (+3 content, Theology increases effect by +1, Communist government reduces effect by -1.)
==12. ReWonder 2.0 ==
Seven new Wonders added + old Wonders made viable.
Formerly, Multiplayer was less than wonderful in how Wonders functioned.  There is no mistake though – It made enormous improvements over Classic rules. The Classic mechanic was so messed up that the first competitive communities were justified to play games with Wonders turned off. In Classic, exclusive Great Wonders gave OP benefits to the nation who got them first, making a horrible imbalance in any game with many humans, but especially in games where there were more players than available Wonders!  Meanwhile, trade routes from Caravans had a far greater ROI than anything else. Expert strategy was 'golden pathed' into Caravans and trade routes. Strategic creativity was limited and repressed. The Multiplayer ruleset made huge improvements by eliminating OP Trade Routes and making most wonders Small Wonders. Caravans were converted from a "Golden Path OP trade generator" into a Wonder-mechanism for diverse strategies and benefits.  With Wonders being as expensive as they are, each civilization had to select a few to define their national strengths. This is excellent and exactly in the spirit of the game. The ROI for Caravans-to-Wonders was not OP like Caravans-to-Trade Routes. Alternate investment into other strategies could be done to rival investments into Wonders. It was a huge step forward: replace OP Golden Path with strategic diversity and creativity, letting each nation define a unique character to its civilization. It sounds great in theory! But years of play-testing revealed flaws:  ReWonder 1.0 had made some Wonders overpriced or useless, or they expired too soon when playing under the accelerated technology pace in massive multiplayer. Out of the portfolio of Wonders, there were a limited number of "good Wonders". Experts usually got the same Wonders in the same order: we arrived right back at the 'Golden Path' that ReWonder 1.0 was striving to fix. We want to be surprised and appreciative how different personalities cook up different brilliant strategies, and learn and grow from what we see.  For MP2, a splendid ReWonder 2.0 Project was conceived to evolve the vision:
*Wonders which were degraded because faster tech pace causes premature expiration, now last longer.
*Wonders which were formerly OP but then nerfed to be underpowered, are re-balanced to an optimum.
*Wonders which became overpriced after a justified nerf, are reduced in cost.
*Wonders which were still OP or inappropriate in massive multiplayer, completely changed to something else.
*'Uniquely Define your Civilization'. Before, everyone picked the same 3-6 Wonders in approximately the same order.  With there now being double the choices, some would assume this doubles the number of Wonder strategies. But combinatorial mathematics make for literally thousands of unique new strategies.
Four new Wonders were imported and adjusted, and three more were invented from scratch. Four old Wonders were then re-balanced to be useful.  Now, instead of half of Wonders being useful and 'Golden Path' among experts, there is a new profile for how Wonders affect the game:   All original Wonders were balanced to be potentially useful, plus seven new Wonders added. Instead of 1/3 of the Wonders being useful, there is a now a menu of over double the useful Wonders. Instead of experts deciding on the same few Wonders in targeted order, they now have to pick a limited handful from a larger portfolio, combining to create unique national character and strategy. This has a HUGE effect on creative strategy and finally achieves Civilization's original goal of letting each tribe become a different kind of civilization with different national characteristics and strengths.  All of this was done while maintaining balance, also allowing alternate strategies which use very few Wonders.
==12A. Ecclesiastical Palace==
Added from Civ2civ3. Cost: 100. Req: Mysticism.
Explanation:  Now you can have an empire with two capitals and two palaces.  Except as noted below, the Ecclesiastical Palace functions exactly like a normal Palace. Corruption rates and incite costs are based on which capital is closest. Under some governments, the original Palace gives a bonus to city production, but this one gives a bonus to gold income. The Ecclesiastical Palace gives the possibility for more complex geographic empire arrangements, similar to what sometimes happened in ancient civilizations. It can equalize fairness for a player who suffered from bad maps, bad positioning, bad luck, or migration/colonization issues. It's an option for a player who suffers more corruption from geography or form of government, and allows "bi-geographic" strategies for non-democracies.  
Effect:   A balance mechanism to counter bad luck in map positioning, encourage more diverse strategies like remote colonization, and support the possibility for governments other than Democracy to be used.
MP2-Brava: Ecclesiastical Palace cost reduced to 90. Automatically rebuilt when lost, like a Palace.
12B. Temple of Artemis
Added from Civ2civ3, but modified. Cost: 250. Req: Mysticism.
Explanation:  The goddess Artemis gives a subtle mystic effect to those who grasp her mysterious ways. This Wonder gives one shield, one luxury, one science, and one gold, to every city with a Temple. You get a tiny bit of everything but no exploitable advantage in anything specific. This Wonder requires a delicate “Artemisian” strategy to leverage the benefits. (This wonder also recovers the "lost shield" from building a city on a tile whose special resource is supposed to give +1 shield (e.g., cities built on grass+shield tiles.)   
Effect:   A mystical Wonder is appropriate for game intrigue. It allows flexibility and creativity in finding slight and subtle ways to get benefits. Obsolete by: Computers.  
==12C. Mausoleum of Mausolos==
Added from Civ2civ3. Cost: 200. Req: Ceremonial Burial.
Explanation:  A grand structure of beauty and memoriam to keep alive the enlightened values of the ancestor king Mausolos.  In every city in the empire, the Mausoleum provides one content citizen for each City Walls and/or Courthouse. It also prevents incitations in all cities. This Wonder is highly unusual and certainly not for everyone, but a player who marches to a different beat can combine these benefits if they have a particular style of play. Obsolete by: Radio.
Effect:   This Wonder gives no content citizens to cities that lack City Walls or a Courthouse. Both of those are costly requirements. Nevertheless, if your strategy already uses one or both of those improvements, then this Wonder provides a similar bonus to other "Happy Wonders", but with a later expiration. 
==12D. Statue of Zeus==
Added from Civ2civ3. Cost:100. Req: Polytheism.
Explanation:  Zeus is king of the gods for a reason. His powers are optimally effective in creating order, efficiency, obedience, and unified discipline.  The Statue of Zeus brings the spirit of this godly culture to your citizens. In every city in your empire, Zeus makes 1 citizen content from military activity. In the home city, it also gives +1 happy citizen and +4 upkeep of military units.  The discovery of Tactics makes all the bonuses of the Statue of Zeus obsolete, except for +1 permanent happy citizen.
Effect:   This provides a way for a Republic or Democracy to erect a statue to get popular support for wars.   
MP2-Caravel: Non-representative governments receive the simple effect of +1 content citizen.   
==12E. Genghis Khan==
Genghis Khan's Equestrian School: Cost: 150. +1 move for mounted units except Cavalry.
Explanation:  To increase a game's strategic diversity, a tried-and-true method is to copy concepts from one mechanic over to another mechanic. For example, the original designers got three Wonders out of one idea:  Wonders were made for Trade (Colossus), Production (King Richard's), and Food (Pyramid). Genghis Khan's Equestrian School is like a "Lighthouse" for mounted units. This Wonder reflects some civilizations' specialization into equestrian lifestyle, allowing nations to “specialize” their national character. Cavalry does not get the bonus. The Wonder expires after the discovery of Mobile Warfare.
Effect:  For the cost of 8 horsemen, a nation may specialize in a mounted warfare strategy that lasts until the early-mid-game. Requirements: (1) Horseback Riding, (2) Must be built in a city with Barracks I (not II). Note: the Explorer is a mounted unit.  
== 12F. Tesla's Laboratory ==
Cost: 220. Upgrades 1 obsolete unit per turn, without itself becoming obsolete. Reduces cost of unit upgrades by 20%. Req: Electricity.
Explanation:  The expiration of Leonardo's Workshop is well-timed for game balance. It encourages the 1800's to happen by penalizing hyper-rush to higher technologies. It balances other aspects in subtle ways. But there were side effects: 1) Loss of continued upgrades overpopulated the late game with older units, 2) Weaker players finally ready to invest in Leonardo suffered a double penalty. 3) Upgrade costs for some later units are so high that it excessively discourages making predecessor units, and/or it's more economical to disband than to upgrade.
Effect:  This Wonder "quantitatively eases" suboptimal side effects. This allows diverse strategies. Players can pursue flexible strategic timing with one or both wonders without feeling forced into the same strategy for every game. There is also a reduction in the unrealistic overpopulation of expired units. Infeasible late game upgrade costs are softened.
MP2-Avant-garde: Cost increased to 220 and also provides 20% gold discount on paid upgrades.
== 12G. Gibraltar Fortress ==
Cost: 350. Coastal Defense in every city. Req: Metallurgy.
Explanation:  Project Neptune re-balanced modern surface ships back into the game. An unavoidable side effect comes when absent units enter a game. In this case, coastal cities are potentially more vulnerable than before. This wonder was tested for cost/value to balance Project Neptune. It creates a counter against nations who spam the newly relevant ships, and/or allows fairness for nations who received more coastal geography. 
== 12H. Agōgē of Sparta ==
Cost: 100. +⅓ move to all foot soldiers. (+1 move if they begin their turn in the city with the Agōgē.) +50% attack to Phalanx, Pikemen. Req: Bronze Working. Obsolete: Gunpowder.
Explanation:  In (Attack+Defense+Movement)/Cost, the Phalanx lacks value compared to contemporary foot units. All proposals to buff it were over-corrections that altered delicate early game balance. A Wonder potentially makes the Phalanx more powerful—but it gives even the normal Phalanx two intangible bonuses: (1) an opponent doesn't know if a Phalanx is influenced by the Agōgē, and (2) it gives the owner of the Phalanx the flexibility to build the Agōgē if needed. This results in a subtle enhancement to ordinary Phalanxes without altering base stats.  
Effect:  The use of foot soldiers in the classical Graeco-Roman era is potentially enhanced, but optionally and at a fair cost. This enables more diverse early game strategies, and fills a hole in early game defensive strategies. 
MP2-Brava: Cost reduced to 90.
==VII. Miscellaneous==
== α. Project Honeycomb: Traderoutes ==
Traderoutes re-introduced in a simplified superior form.
Jump to Design Decisions for a quick list of the new rules.
Introduction: Formerly, there were two choices:
(1) Play in a ruleset with Traderoutes=ON: Manage 25 cities with 4 routes each: 10626 possible combinations (not counting foreign cities.) Discover that a small fraction of those are optimal, and that optimal gives you a compounded boost over other nations to economically annihilate them. Get a spreadsheet, put formulas in scripts, and rule the world! Nothing else compares to the return on investment of Traderoutes. Spend 90% of your time planning and managing them.
(2) Forget that! Disable Traderoutes! Replace them with Marco Polo, and have fun. But did you feel a slight disturbance? Alliances starting to act more like a united clan instead of like sovereign nations with their own identities? Eliminating Traderoutes increased this effect.
In between these extremes is a balanced solution. MP2 is committed to finding it. Project Honeycomb will be conservative and stay closer to Option (2). Future adjustments are reserved: perfection is the goal.
Goals: 1. Traderoutes increase relations between nations: more economic interests. 2. Traderoutes increase sovereignty of nations and slightly diminish "Team-A vs. Team-B." 3. A world of different Civilizations with interlocking and conflicting interests. 4. Traderoutes are simple and not time consuming. 5. No victory for whoever spends more time in a spreadsheet. 6. Investing in a Traderoute has average ROI: this makes them an optional investment strategy. 7. Traderoutes enrich diplomatic possibilities: a nation fearing conquest might offer to produce Caravans to give you routes. A warmonger might find his nation in a trade embargo. Instead of 4-5 allies acting as a united clan, there may be more divergent interests due to routes with other nations. 8. Possibility to play well without establishing a single Traderoute: a. The game has enough other investment choices (doubling of useful Wonders), b. The scarcity of available Traderoutes causes other nations to seek and offer to establish the route.
==== Project Honeycomb 1.0 Design Decisions: ====
# Only one route per city is allowed.
# Traderoute revenue is based only on combined trade of both cities. (No logarithmic distance maths)
# Traderoutes can only be established with a foreign city. Default minimum distance is 12 tiles.
# One city must make the commerce unit, but both cities receive income from the Traderoute.
# Traderoutes are inactive during war, and re-activate when diplomatic relations improve.
# One-time bonuses for establishing Traderoutes are low and do not give any bulbs.
# Like the classic game, Railroad & Flight reduce first-time revenue by ~25% each.
# Instead of a Traderoute, you can "Enter Marketplace" to sell goods, getting a one-time profit. "Enter Marketplace" is superior to Coinage only if both cities are very high trade.
Effects: In MP2, Traderoutes can be compared to investment in an average building. If you have most of your favourite buildings, it's a decent investment. But so is a Wonder, or saving the Caravan for a future wonder. It's a good enough investment that you'll want to consider it for your highest trade cities. In spite of Traderoutes being non-obligatory for superior play, there is something to consider beyond return on investment—traderoutes give the same income to another player. You can establish good relations with neighbours, knowing that war shuts the routes off. You could addict a neighbour to trade income in order to ensure peace. You can boost trade in cities that magnify gold or bulbs from their improvements and wonders; or in cities that need a little more trade to keep them happy.
MP2-Brava: Commerce ships can enter waters of nations with whom you are at Peace, even though they have military capabilities. They cannot attack, however, unless you declare war. This encourages establishing Peace and Trade Routes.
== β. Diplomacy Improved ==
Cease-fire and Peace pacts possible within x turns of meeting a player without an embassy. Default: x=10 turns.
Explanation: The server setting "contactturns" defaulted to 0 in massive multiplayer games: real embassies are needed to give tech/gold/vision, or else trading becomes abusively OP. However, there were bad side effects: 1. It was not rational to invest a large percentage of your GDP in making diplomats. 2. Thus, many nations were forced into "phony war," confusing the meaning of "war." 3. A world of nations in "phony war" disallowed tuning the game mechanics by diplomatic states. 4. Game outcome could hinge on two nations not meeting each other: "I'm sorry but our allies can no longer cooperate because our Explorers met." 5. "Phony war" was such a dominant game element, that often allies were at "war" until the late game. 6. It is quite acceptable for games to divide into allied factions, but it felt like too many games were predetermined this way. This feature liberates new possibilities for the future of Freeciv massive multiplayer.
Effect: 1. Players can do cease-fire or peace without investing a prohibitive fraction of their GDP in diplomats. "Phony war" doesn't intrusively dominate game mechanics: accidentally meeting someone is the trigger for phony war, but the exact same trigger allows cease-fire. 2. Having real diplomatic states accentuates the different government types and their ability to change relations, enter territory, or be restricted by a Senate. 3. The requirement that traderoutes must be foreign and not at war, allows an interconnected world of sovereign interests. 4. Economic blocs can co-exist with military blocs. 5. The significance of casus belli is enhanced. All the above makes a richer deeper game.
==1. Gold Resource==
Special tile “Gold” goes from 0/1/6 to 0/1/8.  In overall values of F+P+T, mathematical modeling of 'true tile value' showed that Gold tied with Iron for last rank among all resources. This is counter-intuitive. Gold is a special find worth fighting for. 
== 1a. Jungle, Tundra, and Resources return to the game ==
The output on these terrain types was so inferior that maps were always set to temperate. This was fixed with: a) Micro-adjustment to terrain base scores and/or b) The ability to improve the tile later, and/or c) Better resources found on the tiles. These combine to re-balance lost terrain and resources back into the game. Resource variety is increased! The Terrain Chart has details.
== 1b. Oasis is a water source for irrigation ==
Nile Effect: +1 food to desert river cities and +1 food to irrigated desert rivers (except oasis.)
Explanation: Ancient civilization flourished on the Tigris-Euphrates and the Nile. Famous civilizations like Egyptians and Babylonians are now possible. This upgrade delivers realism, playability, and geographic diversity.
Effects: a) Oases are water sources. b) Cities on desert rivers get an extra +1 food. c) Irrigating a desert river tile gives an extra +1 food. This does not include tiles that already get the oasis food bonus. See Desert Food Output.
==2. Illegal Action fixed.==
Illegal Action movement penalty removed.  Making a unit lose ⅓ move after an accidental key press punished people with less ergonomic devices, and forbids testing to see if an action is legal. “Change Home City” sometimes gave a penalty when legally performed. All penalties are removed now.
==3. Transform time for Swamp to Ocean==
Changed from 36 to 12.  Map Generator gives two extreme choices.  You can create a map of many islands, or a continent with unconnected lakes. The first choice favors naval units over land units; the second, land over naval. Ideally, all units could participate in a game. Before, landlocked nations couldn't participate in sea wars, often due to about 4 tiles blocking their lake's connectivity to other water.  This change lets sea units rise in importance, a step closer to balanced land/sea games. Let's analyze realism. Before, making a hill under a city took ⅓ the time as dredging a swamp. But dredging swamps takes less time and was done before the industrial age.  The easiest transformation was set to be the hardest!  If a change is more realistic, more playable, and steps toward “the Holy Grail” of land/sea balance, then it's a no-brainer.
==4. Transform time for Grasslands to Hills==
Changed from 12 to 15.   Some have complained that creating hills shouldn't even be possible, while others complain that 2x work rates made it too easy for 6 Engineers to make a 2x defense hill right under their army, seconds prior to TC. The 25% increase in worker-turns may not seem much, but it should be just enough to drastically reduce TC exploits.
==5. Well-Digger==
A:0 D1 HP:10 Cost:5 M:3. Unique unit that can irrigate without nearby water.
Upkeep: 5 shields, 2 food, 2 gold.
The Well-digger is a "patch unit" to give a fair start to nations with no nearby water. On continental maps, about 15% of the time, a nation will get a start with no nearby water. Bad luck can ruin the game. The solution is a unit that can create a water source. To prevent abuse, high upkeep encourages disbanding after the water source is created. To prevent exploitation, the unit's abilities expire after 10 turns in use, or the discovery of Alphabet or Pottery, or the discovery of Writing by any player in the world.
thumb|138x138px|Grassland with a "well".
A Well-Digger can irrigate any Low-Lands tile (not Hills or Mountains), or make a "well." (A "well" is a single river tile that has no source nor destination.)
The typical Despotic city will need at least +2 Food and +2 Production for upkeep. A Well-Digger will fail if: 1) He is outside your borders, 2) He is older than 10 turns in age, 3) You have Alphabet or Pottery, 4) Another player discovers Writing. This is not a unit to fool around with. It is only beneficial to a nation lacking water, in the first few turns of the game.
==6. Canals==
thumb
Engineering lets Workers dig Canals. Travel by ships is the only effect. A canal can be built adjacent to lake or ocean. Usually, this means canals are limited to 1 or 2 tiles. They can be longer if they connect through lakes. Terrain transformation can create water sources for longer canals.
Canals balance Map Generator issues. Islands games favor sea units over land units; Continental games favor land units over sea units. Now, on a continental map, it is possible for landlocked nations to dig canals to open up shipping lanes and naval combat. This is a step toward the goal of featuring land and sea warfare together. A Canal takes the same length of time as a Mine to complete, and can only be done on low-lands tiles, and only adjacent to rivers, lake, or ocean. These three factors limit canal length.
MP2-Avant-garde: Can now be built adjacent to river. This allows connecting water traffic between rivers and oceans.
==7. Foreign Wonders==
Caravans and other Commerce units (except Caravels) can build Foreign Wonders. This increases diplomatic depth. (Reparations, payment for a tech, sycophantic ingratiation, etc.) The two nations cannot be at war.
==8. Helicopters==
Helicopters can use Fortresses to rest and repair. Formerly, this unit lost hit points every turn it was in a Fortress, then died. It can now park at a friendly base without dying there, to rest and repair. Helicopters may land in Forts also, where they neither gain nor lose hitpoints.
City Walls do not give a defense bonus against Helicopters, but rather, SAM Battery does. 
The Helicopter is not a "field unit" - it does not cause unhappiness merely by existing.
MP2-Avant-garde: cost reduced to 95 (was 100), now unreachable to Artillery types, 50% defense bonus when attacked by foot soldiers (Riflemen, Marines, Paratroopers, etc.), Gains vitality adjustments: +1 move when starting in a city or airbase, loses 1hp per turn instead of 2hp, now has 21hp (was 20hp).
== 9. Expelling ==
Added the ability to expel a foreign unit rather than kill it.
 Any non-military unit may be expelled from your nation, which sends it back to its home country:
* Settlers, Well-Digger, Workers, Engineers
* Pilgrims, Proletarians
* Diplomat, Spy
* Caravan, Freight
* Explorer
* AWACS
To expel an Air unit requires a Fighter, Jet Fighter, or Stealth Fighter.
Land units can be expelled by all military land units except Warriors. You can also expel units from nations with whom you have Cease-fire or Peace. Units on Mountains may not be expelled. Units must be alone on a tile to be expelled.
MP2-Brava: new units Tribesmen and Airplane is expellable.
== 10. Capturing ==
The ability to capture units adds extra depth. Capturing a unit converts its nationality to your own.
Only the following units may be captured, which converts them into your own units:
* Workers, Pilgrims, Proletarians
* Explorer
* Caravan
* Freight
To capture a unit requires a foot soldier or mounted unit whose [base non-veteran] attack value is 3 or higher. Units in Forts, Fortresses, or Mountains terrain may not be captured. Units must be alone on a tile to be captured.
NOTE: In longturn games, an idle nation's unit can't be captured UNLESS it is in the capturer's national territory.
MP2-Brava: new units Tribesmen and Train are capturable.
== 11. Steal Map Fragments ==
A portion of the explored world map of the target nation will be stolen, giving you vision of fragments of their world map. The fragments are a "sparsely speckled" revelation of the target nation's entire world map. Multiple thefts will successively reveal more of the target nation's map, with diminishing returns.
This feature increases the richness of diplomatic actions. Diplomats doing the action are spent, while spies have two choices: "Steal Map Fragments" and "Steal Map Fragments Escape." The former will spend the unit but have a higher chance of success (default base setting is 80%), while the latter has a 50% chance and a successful escape of the spy to the nearest domestic city.
MP2-Avant-garde: Map theft now reveals half the exposed tiles as previously.
== 12. Granary Food Storage ==
Capped at 70 maximum. In MP1, the larger cities got, it became progressively more difficult to grow them in non-rapture governments. This is a deliberate and intentional dynamic that should be preserved. However, past 70 it becomes unrealistically punitive for non-rapture governments.
Capped at a grain store of 70, a city with +3 food grows in:
* 24 turns ... with no improvements
* 18 turns ... with Pyramids
* 12 turns ... with Granary
* 6 turns ... with Granary and Pyramids
Compared to rapturing every turn without needing Granary or Pyramid, this is enough penalty for non-rapture governments. This preserves the classical mechanics, advantages and disadvantages of the distinct governments, while smoothing extreme edges that were notoriously unfair. Also see: Non-Representative Governments in MP2.
== 13. Terrain Defense Exploits Adjusted ==
Forest, Swamp, River 1.33x defense (was 1.5x). 
2x moves and high terrain bonuses created imbalanced terrain defense. Experts used this for late-game exploits. The majority of all tiles on the map had a 1.5x+ defense bonus, skewing heavily in favor of defense. 2x move-rates facilitated the Fortify order for 1.5x. 2x work rates could instantly give any tile a 2x Fortress and a 1.5x Forest. 1.5x2x1.5 = 4.5x = 1.5x better than City Walls. Seconds before TC, this could be done to any tile for free. 2x movement had invalidated the defensive importance of cities. Easily obtained high defense bonuses everywhere eliminated a key game element: tactical gamesmanship in movement and geographic positioning.
Can't make Forests or Hills in an existing city.
2x work-rates made it too easy to take advantage of food/trade bonuses by building cities on grass and converting to forest/hills later. The ease of terrain conversion invalidated the sacrifice of founding cities on strong terrain to reap defensive rewards. Cities from entire nations were converted from Grassland to Forest or Hills, degrading realism and playability. 2x work-rates had created a skew favoring defense at the time when the game is meant to equalize offensive and defensive power. It was a mockery to see hills appear under every border city in only one turn.
For quick reference, please see here.
== 14. Fort added. Defense bonuses smoothed ==
Masonry allows Forts which give 1.33x defense bonus. Fortresses require a Fort to exist first. Healing: +10%. Build-time: 2 turns.
Explanation: Formerly, 2x work rates made it easy to create a Fortress in one turn. 2x gave more spare moves to fortify. Only seconds before TC, a unit could occupy a tile with a Fortress being made on it, do a Fortify order, and instantly have 1.5x2x=3x defense against all unit types: 2x movement had created "insta-fortress" tactics. It was easier to defend outside cities than inside a walled city that had paid for every defensive improvement, and to do so free of cost! The new mechanics correct this with a two stage process:
* Fort (needs Masonry) - improvised fortifications that increase defense and provide an outpost. Against Land and Sea units, defenders get a 1.33x defense bonus. Whether occupied or not, a Fort provides vision around it, which is useful for border vigilance. Forts do not claim national territory, but allow a Settler to claim that tile for a new city. Forts give +10% healing over standard healing. A Fort is required on a tile before a Fortress can be made. A Worker needs two turns to make a Fort, and an Engineer needs only one. The most significant bonus of a Fort is that units in it do not suffer from kill-stack.
* Fortress (needs Construction) - can be built on a tile that has a Fort. The +25% healing bonus and 2x bonus against Land and Sea units are unchanged. Unlike the Fort, the Fortress also provides a 1.67x defense bonus against Helicopters, Armor, and Air. Fortresses claim and extend national borders. After Invention, units in a Fortress get increased vision. Build time for a Fortress is 3 turns, identical to irrigation.
The defense chart here documents the bonuses of Forts and Fortresses.
It's still possible to get the highest defense multiples achievable by the legacy Multiplayer Ruleset, but bizarre "unrealism" is replaced with a need for tactical preparations.
MP2-Avant-garde: Bases simplified, refined, and re-balanced.
== 14a. Naval Base added ==
Engineering allows Naval Bases: Sea units get +20% healing and 2x defense. Must be built over a Fort on cardinally adjacent ocean. Build-time: 2 worker-turns. 
Explanation: Freeciv has an undocumented "Pearl Harbor Effect." If attacked in a city, defender firepower for Sea units is set to 1, and the firepower of the attacker is doubled. This gave Foreign ships a major advantage over homeland ships. They either used first strike for a 2x * 2x = 4x Pearl Harbor advantage; or they got the advantage of arriving and finding ships forced to stay outside "Pearl Harbor cities" — they could then use first initiative to cherry-pick the battles in their favor. The "home field advantage" of owning your own coast had been set backwards. Naval Bases give homeland fleets a method to partly counter the disadvantage: a place to rest, heal, and be vigilant.  
Effect: Naval bases are coastal Fortresses with ocean access. Naval bases are the only location where ships can avoid stack death without suffering a defense disadvantage. Ships may enter and receive a bonus from defensive fortifications. Since Naval Bases are built on Fortresses, all other units get the benefits of a normal Fortress. Building requirements: Engineering, Low-land terrain, Fort cardinally adjacent to ocean. 
Notes: The vision bonus from Invention applies to Naval Bases. Irrigation and mines can't be on the same tile.
MP2-Avant-garde: Bases simplified, refined, and re-balanced.
== 15. Timeline changed ==
Formerly, nations were using cannons before 1 AD. People completely ignored the in-game calendar. The in-game year is now calibrated to match the usual pace of games on freecivweb.org. It's now a good indicator of how far advanced you should be.
== 16. Incite cost changed ==
Cost goes from "impossibly high" to "extremely high."
In Classic rules, the cost to Incite Revolt in a city was ridiculously low, and terribly OP. MP rules made it impossibly high, which was an improvement. But it removed a game element. Now it is extremely high but not impossible. It might allow a surprising strategy on very rare occasions. The cost is a complex formula, but cost can easily be discovered by selecting the option when a Spy arrives at a city, then cancelling.
MP2-Caravel: Democracies can now have cities incited, but enjoy a 3x bonus on incite cost.
== 17. Huts a viable multiplayer option ==
Radical luck reduced to minor awards.
Explanation: Huts were an original part of the game. They were inappropriate for competitive multiplayer. Getting a Legion or a free City while a neighbor-nation got killed by Barbarians — this degraded competitive fairness. Nevertheless, huts were originally part of the game and an intangible game element was lost by their removal. The solution is to re-balance huts to fit the scope of the game, and encourage the first few turns to be an exciting era of exploring an unknown world to find and grab advantages before others do.
Effect: There is a ²⁄₇ chance of finding 1 gold. There is a ²⁄₇ chance of finding 2 gold. There is a ⅐ chance of finding 5 gold. There is a ⅐ chance of finding 10 gold. There is a ⅐ chance of finding friendly mercenaries: a Warrior (or Phalanx if your nation knows Bronze Working.)
Use /set huts [0-500] to change the default of 10. Value represents number of huts per 1000 tiles.
== Minor Miscellaneous ==
* Superhighways give +1 airlift capacity to cities size 12 or over (determined by presence of Sewer System.)
* MP2-Brava: Sea Bridge can be built over Lakes and Oceans after researching Steel. Workers or Engineers must be in a ship on a tile cardinally adjacent to a Land tile. Build-time: 6 worker-turns. A Sea Bridge acts as a Road and connects to Roads on the mainland. It allows land traffic and sea traffic to occupy the same tile. Sea Bridges contain a basic Road, and can be upgraded with Railroads and MagLevs.
== Avant-Garde MP2 ==
These changes apply to the 2.1 version of MP2, named "Avant-Garde" /rules mp2-ag
# By default, zoc_purity is enabled. Units who ignore ZoC don't give this ability to units who don't ignore it.
# Quays. A quay is a river improvement. It is a road-type available with Pottery. Stepping in takes 1 move point. Stepping out behaves the same as a road. (Quays require Pottery. Build-time: 2 worker-turns. Like bridges and railroads, it auto-upgrades inside cities when you get the tech.)
#* Ships can Unload Transport (T) in a quay. Units unloaded this way can use adjacent roads with no unload-penalties.
#* Moves needed to cross a river to a tile on the other side:
#** No infrastructure = 2.00 moves = 6/3 moves
#** Quay connected to roads = 1.33 moves = 4/3 moves
#** Bridge connected to roads = 0.67 moves = 2/3 moves
# Canals. Can now be built adjacent to river and ocean. This allows connecting water traffic between rivers and oceans.
# Unload Transport (T)
#* Now works in Naval Bases and Quays, without loss of all moves (was Cities only)
#* Can now be used on any tile for Marines-type units (Marines, AAA).
# Hideouts are a new Base available with Warrior Code. Hideouts can be put in Forests, Swamps, Mountains, and Jungle, but not in someone else’s territory. Only Foot soldiers can make Hideouts. All Land units and Helicopters can hide in them. Other types will be seen. Hideouts are invisible to anyone not occupying the tile. For each turn it is empty, a Hideout has a 15% chance of disappearing. The only way to see a Hideout is to have a unit on it. Hideouts can't stack with other base types. Build time: 1.5 worker-turns
#* The hideouts setting defaults to enabled, but can be disabled in server settings.
# New techs
#* Radar:
#** Is the new tech requirement for AWACS and Heavy Bomber
#** Allows city improvement: Radar Tower. Increases city vision approximately +6 tiles.
#** Allows Engineers to build Radar tile improvement on top of Airbase. Increases vision +3 to +4 tiles.
#* Avionics:
#** Is the new tech requirement for Jet Fighter
#** Is the tech requirement for Ground Strike Fighter (see New Units, below.)
# Conscription allows you to potentially increase the limit on cities making only 1 unit per turn
#* Additional units must be infantry or caravans.
#* Each of the following adds +1 to the limit:
#** Capital city ◦ Factory ◦ MFG Plant ◦ Fusion Reactor ◦ King Richard’s Crusade
#* The city still needs enough shield output to complete multiple units..
# Labor Union changes upkeep on Infantry types from 1 shield to 1 gold.
# Nuclear changes
#* nukes_minor server setting allows completely disallowing any and every type of nuke.
#* Atom Bomb is a weaker nuke, and only kills 4 cardinally adjacent tiles.
#* Nuclear Missile kills all 8 adjacent tiles.
#* Fusion Power enables: Fusion Reactor, cost 200. +75% base production, 5 free upkeep.
#** if nukes_major server setting is set ON, allows Enrichment Facility for making fusion nukes.
#*** Tactical Nuke: a missile which only nukes a single targeted tile.
#*** Hydrogen Bomb: blast area is 21 tiles: the same as a city's workable tile radius.
#**** Population reduction is 75%, not 50%.
#*** Doomsday Bomb: blast area covers approximately 100 tiles.
#**** Completely eliminates all population at ground zero
#**** 75% population reduction elsewhere.
# Wonders
## Great Wall.
##* Cities do not get Great Wall protection until the third turn after the founding of the city.
##* A city must have less than one fifth foreign citizens before Great Wall protects it. (represents time to extend the Great Wall.)
## Tesla's Laboratory costs 20 shields more and gives 20% gold discount on upgrades.
## King Richard's Crusade - gives the "Conscription Bonus" of making more than one unit per turn without needing Conscription tech..
## JTIDS is a new Wonder. Infantry units get +1 vet level. Odds of promotion are increased.
# Police Station
#* unchanged: keeps the new “secret police” bonus for spies. (+1 vet level)
# Unit Changes
## Fighter types can Vigil - orders them to auto-attack adjacent units if:
##* The other unit is an airplane type, Paratrooper, or Transport Helicopter.
##* The Fighter has better odds to win by attacking instead of defending
##* The Fighter is not the only unit defending a city
##* The Fighter has been ordered to Vigil
##* Move limits for Vigil: Fighter 2. Escort Fighter, Jet Fighter: 3. Stealth Fighter: 4.
## Helicopter
##* unreachable to Artillery types
##* 50% defense bonus when attacked by foot soldiers (Riflemen, Marines, Paratroopers, etc.)
##* "vitality" adjustments:
##** +1 move when starting turn in a city or airbase.
##** Loses 1hp per turn instead of 2hp.
##** 21 hp = “gets one free turn in the air”
##* City Walls don't give defense bonus against Helicopters. SAM Batteries do.
## Medium Bomber
##* available with Advanced Flight. (Heavy Bomber moved to the new tech "Radar")
##* the later availability allows this unit to be more effective:
##** upgraded from 6A 13 moves, to 7A 15 moves.
##* "Soft Field Unit".  causes 1 less discontent citizen when non-aggressively deployed.
## Carrier
##* Costs 155 and carries 9.  (Was 160 and C:8)
## Anti-Aircraft Artillery
##* gains the "TransportDefender" flag: able to defend while transported, even on ocean tiles.
# New Units
## Transport Helicopter. This helicopter can't attack, but carries 3 land units (see restrictions in the helptext.)
## Dive Bomber A3 D3 18M. Exerts ZoC. +50% attack vs non-air, +33% defense vs. Anti-Air.
## Ground Strike Fighter upgrades Dive Bomber. A7 D4 21M Fuel:2. 33% defense vs. Anti-Air.
# Communism
#* pays 10 less for Dive Bomber
#* pays 5 less for Riflemen.
# Supreme Court
#* no longer gives bonus against hostile diplomats, but enables Homeland Security building which does.
# Casus Belli - Casus belli is now triggered for:
#* Poison water, Pillage tiles, Capture unit
#* International incident for detonating nuclear devices -- allows any nation to cancel its treaties with you.
Minor / miscellaneous:
# anti-Diplomatic bonuses for Courthouse, Police Station, Homeland Security are identical and stack together.
# Diplomat vet bonuses are improved and better balanced.
# Airbases heal Air units +15% per turn (was 0%).
# Fanatic upkeep for non-fundamentalist governments is higher.
# Starting commerce Units: (1) Can be given a Home City for Trade Routes, (2) Have no tech restrictions for Build Wonder.
# The +1/9 "ultra-elite move bonus" for v4+ vet levels starts to take effect in v3 Marines, since v3 is when Commando bonus begins.
== Brava MP2 ==
These changes apply to the 2.2 version of MP2, named "Brava" /rules mp2-brava
# New unit: Tribesmen. A0 D1 HP5. Req:None (game start unit)
#* allows more early exploration
#* allows (weak) city defense
#* primary use is for disbanding to supply bonus shields to accelerate the early game.
# New unit: Spy Plane upgrades AWACS. This unit is a stealth aircraft. Req:Stealth
# New unit: Airplane can carry diplomatic units. Req:Flight
#* can be expelled by fighter types
#* gains movement points with each new aviation tech
# New unit: Train. Req:Railroad
#* Commerce unit
#* Cargo/Transport unit. Valid cargo: any unit with <=2 moves, and also balloons
#* Unreachable by pre-gunpowder units
#* Capturable (but not by by pre-gunpowder units)
#* Foot units can load onto Trains on any tile with Load Transport (L)
#* Foot units can disembark by stepping off to an adjacent tile.
#** Except for Marines/AAA, stepping off uses up all move points.
#* Foot units can Unload Transport (T) with no movement penalty:
#** in a Quay, or any type of Base, or in a City
#** if unit is Marines or AAA, can do this on any tile
#* The Train re-balances two major nerfs that Multiplayer-branch rules caused for Foot Soldiers:
#** loss of infinite speed rails made Foot units far less effective, relative to mounted units
#** 2× movement resulted in Foot units reduced by ¼ the "reaction area" as mounted units (A = πr2)
# Trade is no longer a requirement for making Wonders.
#* Removes the artificial impossibility of making Bronze Age wonders in the Bronze Age.
# Commerce ships can enter Peaceful waters but cannot attack until a war declaration.
#* This allows Establish Trade Route or Enter Marketplace with nations with whom you're at Peace.
# Stone Age herds of wild game appear in Grasslands and Forests for first 15 turns (until 2500BC).
#* They provide a temporary food bonus to the tile, but only during the turn they are present.
# Robotics is now needed for Plastics
#* forces Armor to be required before Armor II is available
# On average, Fallout lasts around 5 turns before disappearing (20% chance to disappear each turn.)
# New server setting killcitizen_pct defaults to 60% (was 100%).
#* This setting regulates the chance of a city losing 1 population after losing a battle to certain land units.
#* Improves viability of early game warfare, when most cities are size 3 or less.
# Ecclesiastical Palace
#* price drop to 90 (was 100).
#* like a Palace, this improvement relocates at random when the city is lost.
# Agoge of Sparta - price drop to 90 (was 100)
# Pre-civilized tribes enjoy a +⅓ move bonus. Building your first city eliminates the bonus. (Sedentary culture.)
# Explorer
#* cost reduced to 25 (was 30)
#* Req changed to Map Making (was Seafaring)
#* slight vision boost from sqrt(4) to sqrt(5): i.e., from 2 tiles to 2.24 tiles.
16. Sea Bridge
* Requires the technology Steel
* Built over Ocean and Lake: (requires Workers/Engineers to be in a transporter ship)
* Acts exactly like a road for Land units to pass over.
* Does not block Sea traffic.
* Does not give any other bonus.
* Must be built cardinally adjacent to a Land tile.
* Railroads and MagLevs may be built on top of it.
Minor/ misc.
# Freight unit must use and can only use roads.
# Transporting units can't fortify until unloaded.
# Bug fixed where Magellan's Expedition didn't give vet bonus to Caravel.
# The +1/9 "ultra-elite move bonus" for v4+ vet levels starts to take effect in v3 Marines, since v3 is when Commando bonus begins.
# Clean pollution can be done while units are transported.
#19.October.22 - Superior canal mechanics and ability for irrigation off canals added to MP2A and MP2B, for consistency. 
== See next ==
After MP2 Avant garde and MP2 Brava, documented here, MP2 Caravel is the next MP2 release.
Multiplayer Caravel Summary