Supply Model

Supply affects the amount of resources that industries and units receive. Upgrades and units must have a friendly-held route to a military bases, supply depot, or city. The larger the base or city, the greater supply it can provide to the surrounding territory. For peak production, an industry must be in full supply (i.e., 100%).

Supply is amplified by highways and railroads Looking at the supply model (Hotkey S), one may notice that highways and railroads are more opaque than the surrounding territory, as they function like arteries in distributing supply. Highways are more effective than railroads in amplifying supply, and offer movement bonuses to units as well. The effectiveness of these highways and railroads is affected by a region's level of Infrastructure funding, which can be found in the Interior panel.

## Factors affecting supply levels

* Proximity of military basesand cities

Closer is better. Bases do more than cities (at least the larger bases), and larger bases provide more supply than smaller bases.
* Terrain

Mountains, jungles etc. will degrade supply more than plains.
* Highways and railroads

These improve supply when run from bases and cities to hex in question.
* Infrastructure funding

Ministers often cut spending here
If the Quality Rating is 100%, you'll get the values mentioned in the lower section. Lower Quality Rating leads to less effective supply objects, however higher Quality Rating gives all supply objects a bonus (Applies to SRCW 7.2.2)
* Research of technologies such as Urban Renewal, High Speed Trains, etc.

## Sources of supply

100% = 1.0 Hexes = plots = tiles

Generally supply spreads over an area surrounding "supply centers". These can be cities, industrial or military complexes or special buildings. There is a maximum range to which supply spreads. If any hex is within range, it get's its supply from this "supply center", but the supply level will be lower the greater the range to the supply center. If it is within range of more than 1 supply center, let's say 3, it gets the highest value

Example:

* 1 supply center existing of a city (0.4), but at distance only 0.24 supply is left
* 1 supply center existing of a military complex, air base and supply center (0.9), but at distance only 0.65 is left
* 1 supply center existing of a city and sea port (0.8), but at distance only 0.57 is left

This hex will determine the highest supply it can get is 0.65, so you supply level will show 65%

### Base Objects

#### Communal

* Capital City: 0.6

Can be any of the communal objects below
* Mega City: 0.6
* Large City: 0.5
* Metropolis: 0.5
* City (Common): 0.4
* Town: 0.4
* Small Town: 0.4
* Village: 0.3
* Small Village: 0.3

#### Industrial

* Oceanic Complex: 0.6
* Industrial Complex: 0.1

#### Military

* Military Fortress: 0.5
* Military Complex: 0.3

### Partly Stackable Objects

Following objects can be added to any of the 'Base Objects', but only once they add to supply. This means, even if you were able to put 2 Air Bases and 2 Sea Ports on any hex, you'd still have only 0.4 added to your supply level

* Air Base: 0.4 (Air Field has 0 effect)
* Sea Port: 0.4 (Sea Pier has 0 effect)

### Full Stackable Objects

Following objects can be stacked on top of anything up to 100%(1.0)

* Supply Depot: 0.2

### Negative Objects

* Barracks with communal base: 0.0 No effects seen
* Barracks with military complexes: -0.4 (This basically means, you shouldn't place them too soon!)
	+ Example:
		- Military Complex 0.3
		- Air Base +0.4
		- Sea Base +0.0 (Sea Base and Air Base don't stack with each other)
		- Barracks -0.4
		- Supply Depot (3slots) +0.6
	+ Maximum is only 0.9 - 90%
* here's the trick (as of Supreme Ruler Cold War) first get your supply level up to 100%, or whatever you want, and then build your barracks afterwards!) the once the level is up, it doesn't go down by placing barracks)

I'm not sure if the barracks are a bug or something. Especially since their -0.4 only has effect if you build them before your supply levels are up (they kinda prevent them going up) but once your supply levels on a hex are up, you can place them and the supply level remains on it's high value (as if the barrack has a 0.0 effect)

### Notes

This information comes from a user named: "bvb" link: http://www.bgforums.com/forums/viewtopic.php?f=63&t=19303 Little information I couldn't verify, and updated with my own observations

If any information provided here is incorrect please update the information for future readers. If you want to update these values, keep in mind supply levels are not raised instantly.

#### Example

I used the cheat 'breakground' to instantly place those objects for testing purposes

* Hex with base supply under 30 (Mongolian dessert or something)
	+ Turn 0: 20 (this supply level comes from a distant "supply center", as explained above how a hex determines it's supply)
* Add a military complex on top of it (gives this tile a base of 0.3)
	+ Turn 1: 30 (Now the own supply is higher then the highest supply from a distant "supply center" and thus it's own "supply center" overrides the supply from the distant "supply center"
* Add an air base on top of it (+0.4)
	+ Turn 2: 40 (+10)
	+ Turn 3: 48 (+8)
	+ Turn 4: 56 (+8)
	+ Turn 5: 63 (+7)
	+ Turn 6: 70 (+7)
	+ Turn 7: 76 (+6)
	+ Turn 8: 76 (+0)
	+ Turn 9: 76 (+0)
	+ Turn 10: 76 (+0)
* Add supply depot
	+ Turn 11: 86 (+10)
	+ Turn 12: 96 (+10)
	+ Turn 13: 97 (+1)

Obviously there is some supply more than should be 0.3 + 0.4 = 0.7 and not 0.76

### Placement example, hints

If you wish all your hexes to have 90% supply level the minimum. You might start with giving your Capital an Air Base so it gets 100% supply. You then go to the closest tile getting 80% and place enough supply objects on it to get 100%. In the middle between those 2 you'll get something around 90% (maybe 1 or 2 less or more) and spread your supply like this. Remember, if you do this while infrastructure level/spending is lower then 100%, if you later in the game increase your infrastructure spending, the supply will gradually increase. Getting 100% everywhere is possible only in theory:"You'd have to place supply centers virtually every single hex" Since funding everything in the beginning is pretty tough, you might want to create 100% supply centers every distance from your capital where you'd have a supply of 60% from your capital, it means all tiles will be around 80 or higher. Air Bases and Sea Ports are IMHO the best option to start with to spread supply, as they give the same supply level as 2 supply centers, but take less soldiers to maintain them. The difference is money is not that big to be of our concern.

## Construction and build time

To build an upgrade, the hex it would be in has to be in supply. On ground hexes, this can be a rare problem in some isolated lands such as South West Australia's desert and, more commonly, on newly captured territory that has not built supply yet. On water hexes, many players forget the need for a sea base or pier. Not only do you need this during construction, but you need it to continue operating upgrades (oil derricks) and units.

The exception to needing supply in a hex is that Engineering units are able to build Air Strips, Sea Piers, Supply Depots and Emplacements in out-of-supply areas. Having multiple engineering units acting together will increase construction speed somewhat.

How fast structures are completed, their build time, is affected by the level of supply of the hex it is constructed in. For example, in an area at 45% supply, an industrial goods plant might take 83 days, while in an area at 90% supply it might take 63 days. At the extreme end, very little supply can make building in some barely-in-supply hexes close to impossible. This is true of roads, which can be completed much sooner near the better in supply region than the extremity to which you are building.

## Production

The amount of goods an upgrade can produce is affected by supply.

## Military maneuvers

When a unit captures a hex, the hex doesn't provide supply right away; it needs time to build up. At least a day is needed to build any level of supply. Units are always using supplies, but in the time that they are in unsupplied territory, they dig into the supplies and petrol they carry with them. If out of supply too long, they can run out.

Units restock their supplies faster in an area of high supply. To gain supply as fast as possible in enemy territory, consider advancing along a highway or railroad and have infrastructure fully funded. Also, paradrops or seaborne invasions can be made on cities or military bases which become a self-sustaining source of supply.

When a unit runs out of supplies, it becomes unable to fire and its morale *may* lower (unconfirmed). If it is out of petroleum, it will be unable to move as well. Units out of supply are obviously very vulnerable, being unable to defend themselves. A common tactic employed by both players and the [/old.supremewiki.com/index.php/AI AI] is to move behind a unit to cut its supply. When a unit is out of supply or nearly out, its HUD color will be red.

Units vary in their rate of supply and petrol consumption. Some of the heavier units, such as artillery and tanks, can quickly run out of supply in enemy territory. This is exasperated some technologies that increase ammunition consumption, notably the very popular ERFB-BB Ammunition (increased range) technology. Lighter units such as Light Infantry and LAVs/VABs use less supplies and can usually operate longer without supply, but this depends also on the amount of supplies and petrol they carry. An armored unit such as the VAB can actually move further over unsupplied territory than a light infantry unit because it carries almost twice as much petrol, but with very similar consumption rates.

Supply trucks and aircraft that have spare cargo capacity can be used to resupply units. Just move a one into the hex a unit that needs to be resupplied and supplies will transfer. To restock the truck or cargo aircraft, move it back to in-supply terrain and wait a bit.

## Common problems

When my units attack, their health bar (HUD) turns red and they refuse to fire. They even retreat.
This happens when a unit is out of supply. Check the supply overlay by pressing "S" on your keyboard--how far away are hexes of your own colour? You need to either wait for supply to 'catch up' with your new territory, or send in a supply truck or helicopter.
I can't build in an area.
If a hex can't trace supply back to a city or base, for instance some ocean hexes or an isolated ground hex, it cannot be built upon. NOTE: Engineers can be used to build Air Strips and Sea Piers in unsupplied territory. Place an engineer where you want to build and then you will be allowed to build there, even when there isn't supply available. Put engineers next to the shore where you want to build.
# SR2020 Warfare Guide - Chapter 14 - Supply

Submitted by Balthagor on Fri, 01/04/2013 - 20:29
All of your military Units - land, sea, air and facility units are worthless without a source of Supply. No supply = no beans, no bullets, no buildings and no billets. Supply is generated by cities (settlements), bases and factories. It flows across your Region via roads and railroads where it furnishes fuel, material and energy to your Units.

Combat is impossible without the logistical support furnished by the Supply system. Defensive combat within your own Regions is usually not a problem, unless you have moved your Units to some remote hex far from roads and improvements. Naval units in your supplied home waters are automatically re-supplied with fuel, supplies and missiles as long as they stay on your supplied sea hexes. Aircraft can only re-supply from air-fields, or in some cases from air tankers or aircraft carriers.

In heavily supplied allied Regions their supply will sometimes "spread" over the friendly border and into your Region. However you will still receive your own supplies, not theirs.

At sea, supply is generated by sea-piers and these supplies "flow" along the sea hexes along your coasts. This ocean supply effect decreases as you move farther from the sea-pier. Transport ships can be used to re-supply naval units in un-supplied waters. Friendly Oceanic Complexes (oil platforms) can be used to resupply your ships and landed helicopters and VTOLs.

When invading another region you can quickly out-run your "supply line" that reaches back to your established Region. Since new supply is generated by "improvements" like cities and bases, it is possible to generate new sources of supply as you advance and capture the enemy's structures. However it takes two days for a captured city or base to begin producing and distributing supply again and any such structure that you captured will automatically be damaged during the turnover of ownership. Otherwise your force will have to rely upon supply trucks and aircraft, or else they will have to stop and wait unit the supply line from your established Region spreads to their current location.

This is why it is vital that you include supply units with any land or sea force of units that you deploy. Supply units have the ability to load discreet supplies such as fuel and cargo from supplied hexes and then deliver them to your supply-hungry units at the battle-front. Land units can receive re-supply from supply trucks or from supply aircraft that hover overhead.

Supply units air-dropped into enemy territory will land empty of supplies, so your airborne assault teams must rely upon their on-board supplies and fuel or else receive them from fly-over transport aircraft.

Ships can be re-supplied from tankers, carriers and transport ships that are not otherwise full of passenger units. Be aware that some transport ships are huge and take an extremely long time to re-load, even in very well supplied hexes.

If you give your DM control of you supply units it will do a pretty good job re-supplying your units. Otherwise give your supply units plenty of initiative via the ROEs and set them to "Patrol" between the battle-line and a well-supplied hex.

This bears repeating - include supply units with any land or sea force of units that you deploy.

## Unit Freeze

If you set your combat units with enough initiative in the ROE's, they will leave the battle-line on their own once they run low on supplies. Artillery runs out of supplies quickly and are infamous for doing this. This is an awkward, hard-to-manage situation.

But a worse situation is when you land units do run out of supplies at the battle-line. Even if they have fuel, they will not move until they are re-supplied. This is referred to as "Supply freeze". Land units without supplies will not accept your commands. When you check their status box, under "Orders" it will say "Awaiting supplies". Meanwhile your frozen units are defenseless from enemy attack.

Another situation where unit freeze can occur is if your units are located in a neutral region on a transit treaty. If you DOW this Region then suddenly all of the supplies will disappear from your Units and they will all "supply freeze" until your supply units can re-supply them.