Spelljamming Rules

==Introduction==
Imagine a universe where square worlds spin around gemstone suns. Where planets lie cradled in the roots of an oak tree so vast its leaves twirl around brightly burning suns. Where Tallships of wood sail the void between worlds and do battle with Gun and Cannonaide, spell and sword, where an asteroid may be a safe harbor, a slaver's den, or a hungry creature eager to devour any that pass by. Where daring swashbucklers and scoundrels race for fantastic treasures and literally touch the stars. Where terrifying beasts with the power to destroy whole planets roam. Welcome . . . to Spelljammer! And By Extension Endless Aetherium
In any Spelljammer campaign and especially in this shard campaign, the fantastic is possible and one is limited only by the depths of their imagination. Sailing ships, enwrapped in bubbles of air, travel empty Wildspace, moved by the power of their mystical Helms. Gravity is a matter of convenience, where a crew of adventurers can tour the bottom of their ship, and worlds come in all shapes, colors and sizes. Whole solar systems are surrounded by Titanic spheres made of an unbreakable, crystalline substance to protect them from an ocean of swirling light and color, the flammable Phlogiston, which divides the void between stars
== Space ==
Wildspace is what comes to mind when we talk of "Space." It is the vast emptiness that lies between the planets and the stars. All the celestial bodies within a Crystal Shell float in the airless void called Wildspace. Conventional (meaning "those that take place on the material plane") interplanetary journeys around a solar system take place within Wildspace. The regions of Wildspace are primarily airless vacuums, but the cosmos is large and vast with plenty of exceptions to the rules. Wildspace is not truly a void, although it is often referred to in that way. There is plenty to explore and conquer. Life and Time are the only constants. Home to all manner of things, there is no tell what adventure can be found in Wildspace.
== The Crystal Sphere ==
All Wildspace is bounded by an impenetrable crystalline shell, called a Crystal Sphere. Inside the Crystal Sphere is the airless vacuum of Wildspace and the planets where adventures take place. Outside the Crystal Sphere is the rainbow expanse of the Phlogiston and more Crystal Spheres bobbing like Islands afloat in an infinite sea. You can consider a Sphere to contain one solar system, but that's a tremendous oversimplification.
The size of a Crystal Sphere is determined by the size of the planetary system inside. Usually a Crystal Sphere has a radius twice as big as the orbital radius of the outermost planetary body in the system (ie. the distance from the shell to the outermost planetary body of the system is the same as the distance from that outermost body to the center point of the system). Due to their great size, the outside of a Crystal Sphere appears perfectly flat when viewed up close. The curvature is so gradual that it is completely undetectable to anyone who is close enough to see the Crystal Sphere through the obscuring Phlogiston. The spheres consist of an unbreakable, murky, ceramic-like material of unknown origin.
Some legends state (and most theologians agree) that the smooth-surfaced shells were created and positioned by the gods themselves to protect their worlds from the ravages of the Phlogiston, which is held to be the prime matter of the universe. Less charitable philosophers maintain that such shells were placed by an even higher authority to keep gods and men in and confine their activities. Whatever their origin, the Crystal Shells are uniform. All appear as great, dark, featureless spheres of unidentifiable matter.
The Crystal Spheres are definitely solid. They have no gravity along either their interior or exterior sides (an exception to the rule that all large objects have gravity). 
No magic has been found that can damage or alter the surface of a shell, with the exception of those spells which cause portals to open. 
Even this is believed to be nothing more than an artificial triggering of a natural phenomenon, as naturally occurring portals appear seemingly at random. They are apparently immune to the effects of wishes and even the wills of the outer planar powers.
=== Movement in Space ===
Every ship in motion has a Speed, which is the distance that the ship can move in a given period of time. On a hex space (hexagonal spaced) grid, each ship takes up one hex space, which refers not to the size of the ship itself, but the size of the sky it controls. Hex spaces do not take up a specific distance, but are rather more about the story being told in the theatre of the mind.
Your ship Speed is determined by the MR of the ship itself and your Helm Rating, using the formula below:
Speed = Helm Rating + MR of Ship
In Combat and other tactical scenarios, the speed of the ship is the number of hex spaces it can move per round and/or the number of hex facings it can change.
Out of Combat and other tactical scenarios, A Spelljamming ship is outstandingly fast; even a mountain transplanted from a celestial body (with a Spelljamming Helm installed) will travel 100,000,000 miles per day (about 4 million miles per hour) in Wildspace regardless of ship Speed. 100 million miles per 24 hour day sounds like a lot (it’s approx. the distance from the Earth to the Sun)
What slows movement among more crowded inner planets is the presence of multiple, occasionally overlapping, Gravity Wells. When a ship moves to the Gravity Well of a large body (10 tons or greater), or when Tactical Combat is detected automatically by the Helm, it immediately drops to tactical speed of one hex per Speed per round until it has left the planet's Gravity Well, or combat is concluded. 
A ship caught this way can descend to the surface, move around in the atmosphere, leave the area, or proceed with combat. Aside from the most basic awareness change, the “sudden stop” does not affect anyone on the ship, and the safety appears to be built into the magic of the Helm itself.
On average in the gravity well of a planetoid, this translates into about 10 miles per hour or about 240 miles per day. Some vessels may be faster in that regard, while others may be slower.
Tactical scenarios near a large body move this way due to the close interaction with a planetoids atmosphere, gravity well, and weather conditions.Ships move on a hex grid, and movement is determined by Speed. 
The Speed of your ship is the number of facings that the ship can change and/or hex spaces it is able to move per round of combat. Facing a different direction in the hex space you're in, or moving one hex space forward uses one Speed. You deduct one Speed to turn the ship towards a different hex side adjacent to the port or starboard (left or right) of the current bow (front) position of the ship. You may also spend one Speed to move forward into the hex space adjacent to the current hex space where your ship resides and faces.
For example: 
The Monarch, a merchant ship, has a Speed of 8. The Helmsman piloting The Monarch wishes to move away from an oncoming ramming attack directly from the bow (front) by an enemy Pirate vessel. The Helmsman spends two Speed to turn the ship to the starboard-side (right) two facings of the hex that it currently resides in. The Cannons onboard The Monarch are ordered by the Gunner to be fired at the oncoming Pirate Vessel, scoring a direct hit! The Helmsman then urges the ship forward four hex spaces in the direction that the ship is now facing, spending four Speed. A single Speed is then spent to turn port-ways (left) one hex facing, and the ship uses its' last Speed for the turn with a move forward one hex, readying for the next round.
Any ship without a Helmsman, a broken vessel, or any errant detritus floating about in the area moves at a constant speed in one direction across the battlefield using it's last known speed. Be wary, as brigands and other ne'er-do-wells may be hiding just beyond a floating piece of space junk, laying in wait. . .
=== Time in Space ===
In general, time between two planetary bodies can be figured as:
* Time for take off (in rounds) +
* Time to escape gravity well (in rounds) +
* Time to cover distance to next planet (rounds, minutes, days, weeks, or months, as appropriate) +
* Time to land (in rounds)
=== Travel Time ===
Travel time between the various planetary bodies is taken into consideration, as there is only so much air that the ship can bring with it. For ease of relaying travel information, planetary motion isn't a major factor determining travel times and positions of each planet. 
Listed below is an example for average travel time from Yal’Rena to the various other planetary bodies in the Verithspace system:
Yal’rena	Planet
13hrs 	Morad
6hrs 	Nekhemra
6hrs 	Meloris
24hrs 	Gygax
2 days 	Erathis
3 days 	The Great Guard
4 days 	Illmat
For more information on how a universe is laid out and created, as well as optional rules, see the chapter on Celestial Mechanics.
Takeoff & Landing
When taking off from a planetary body, a certain amount of time is required to allow the Helm to overcome the force of normal gravity and fully leave the planets’ gravity well. The amount of time it takes to leave the planets’ Gravity Well are listed below:
Size A, B, & C – Ten minutes
Size D, E, & F – Twenty minutes
Once a planet's Gravity Well has been left, full movement at Spelljamming speed can begin. 
Temporary ships (Those that have been cobbled together from broken vessels), cannot make a takeoff or landing safely and will Crash, completely destroying the vessel.
Dungeon Master’s Notes
Optionally, you may refer to the weather rules in the Dungeon Masters Guide, pages 109-111 and 117-119.
In None and Light wind conditions, Normal takeoff and Land times occur.
In Strong Wind, Light Rain, or Light Snow, takeoff and land times are 2x normal time.
In Heavy Wind, Heavy Rain, or Heavy Snow, takeoff and land times are 4x normal time.
In Hurricane winds, no safe takeoff or landing is possible. If forced, roll 1d10. On a 1 or 2, the ship crashes and must be repaired before travel can resume.
“Ner a Sight seem afore, can any vista compare… then to whirling Dance of the Rainbow Seas - Old Verithian Sailor’s Song”
==The Phlogiston==
Also called The Endless Aetherium, or The Flow, the Phlogiston is a turbulent, unstable, multicolored, fluorescent gas-like medium which fills the regions between Crystal Spheres. For lack of a better definition, it is a sea in which all Crystal Spheres bob, weave, and float. Its currents carry the spheres around a shifting stream, ever moving. Very little is known for certain about the Phlogiston, except for every system known is encased within a Crystal Sphere, and no known planetoids exist floating freely in the Phlogiston. Essentially, the Crystal Sphere keeps the Wildspace in and the Phlogiston out (which is a tremendous simplification, but it is easy to grasp).
Phlogiston also cannot exist inside a Shell, and all attempts at doing so causes the somehow-captured Phlogiston to have vanished upon inspection, leaving no traces. The rainbow ocean allows Spelljamming ships to attain greater velocities. These speeds have defied measurement since the phlogiston is without permanent landmarks or markers.
In a general sense, it takes from 5-100 days to travel from one Crystal Sphere to another. The sphere reached is random, unless you have either a guide or a device installed aboard the ship to show you the way. Shortcuts exist through spheres to other spheres. The Mapped and Charted expanse of the Valmirian Cluster, also known as the Coiled Junction for example. Thanks to the efforts of the West Valmirian Shipping Company has a network of Lighthouses and outposts that mark the fastest shipping currents through the section of the Rainbow Sea in which the Sphere of the Coiled Junction Rest. 
Outside the Junction some spheres drift into and out of proximity with each other, so that just because you reach an area once does not mean that you will find it again.
It is also violently and exponentially flammable. An early researcher (wanting to have a better look at some of the ocean he captured) lit a match with the intent to burn a candle. Upon sparking, an explosion immediately erupted from the match head, taking the researcher's hand with. . . In short, a match acts as a powerful firework, a firework acts as a fireball, and the devastation that a fireball would cause may take even the largest ships (and all hands) with it. Spellcasters should be mindful of this Danger.
==Magic in the Phlogiston==
The effects of certain arcane and divine spells and spell-like abilities are limited in the Phlogiston that lies between Crystal Spheres. Individuals with magical abilities may use their powers to operate a Spelljamming Helm, allowing them to maneuver their ships across the stars. All magic operates normally within any Crystal Shell, but is severely hampered in the Phlogiston.
A Cleric receives her spells through the offices of her deity, and the Druid and Ranger pull the very essence of terrestrial bodies themselves. Warlocks have been given the source of their power from their Patron. A Diety’s or Patron’s effectiveness ends at the Crystal Shell, and no known terrestrial-based nature exists in the Flow. Warlocks are unable to contact their Patron (as Planar contact is nonexistent).It is impenetrable to extra-dimensional magics, and as a result the gods and other powers have no sway there.
=== Divine Magic ===
While any god or power may not be considered “recognized” within a sphere unless it has worshippers in said sphere, the eternal wars of the gods have brought about alliances.
In Endless Aetherium, A Divine Caster is Unable to cast spells above 3rd level in the phlogiston and a sphere that a character's deity is not worshipped in. It will be necessary to contact a local church with a deity that has an alliance with your God for the necessary steps to regain full spellcasting ability. (In general, Gods with the same or similar Domains tend to have an alliance.) If your deity is not worshipped or have an Alliance in the Crystal Shell you are touring then then you suffer penalty until a connection is restored with the Contact Home Power Spell
Another route that can be taken is You can begin the process of starting a church by performing the Sacred Rites of your deity, and gaining renown. See Pg. 129 of the The Dungeon Masters Guide for downtime activities or Pgs. 123-134 in Xanthar's Guide to Everything for a revision of these rules. Generally, several weeks of daily performance of Sacred Rites and proselytizing can generally either start the recognition of your deity in whatever Crystal Shell you are visiting, or attract the attention of a deity that is able to relay power. The DM is heavily encouraged to work with the character to set a reasonable amount of time based on the limits or freedoms of time in the campaign. 
=== Teleportation and the Realms ===
Spells and Spell-like abilities that call upon beings from the surrounding area will not function if none of those creatures are located within the spells range (ie. Calling upon local animals to aid in battle or to give information can't work if you're millions of miles from a habitable place). Conjuration/Summoning spells will not work in the Phlogiston if they summon extra dimensional monsters or powers. No power, God, elemental, or other meta-planar creature can be summoned in the Phlogiston, and any spell that attempts to do so will automatically fail. In addition, any spell that places the caster in contact with an extra dimensional power automatically fails in the Phlogiston. Below is a short list of the kinds of spell that fail to work while in the Phlogiston:
* arcane gate
* astral projection
* blink
* conjure animals
* conjure celestial
* conjure elemental
* conjure fey
* commune
* conjure minor elementals
* conjure woodland beings
* contact other plane
* demiplane
* etherealness
* gate
* Leomund's secret chest
* Mordenkainen's magnificent mansion
* planar ally
* plane shift
* teleport
* teleportation circle
* transport via plants
* tree stride
* word of recall
Travel between the planes of existence functions normally within the various Crystal Shells. A character in Wildspace may go ethereal, enter the Astral Plane, or open a gate into one of the outer planes. In the Phlogiston, however, the dimensions cannot be accessed. Therefore, devices and spells (Bags of Holding, or Contact Other Plane) will not function. A device or spell that holds objects in external dimensions will still hold them, but the items cannot be accessed.
==Fire==
Within an air envelope, fire burns normally. Outside of an air envelope, there is a vacuum that will not support fire. Magical fire (such as the Fireball spell) will work in the vacuum of space as it is the sudden creation of fire that requires no air, though it will not cause anything outside of an air envelope to burst into flame, as no air exists to support the fire.
Within the Phlogiston, however, fire works all too well. This affects both non-magical and magical flame. All effects from creating a flame (from the spark of a match to a 9th-level Fireball) are increased by 3x and explode immediately upon existence. This is such that igniting a match will cause serious burns (1d6 damage), and casting a 3rd level Fireball will cause 24d6 damage centered where it is cast (For example, in the hands of the Person casting it). The Damage caused by this effect is non-reducible. It is advised to extinguish all flame-based light on the ship, and to avoid bringing Alchemist Fire into the Phlogiston.
A Grim Fate awaits sailors who trifle with flames in the Phlogiston
==Gravity==
There is a reason everything from ships to asteroids can drag its own pocket of atmosphere around through space, and the reason is gravity. This is also the reason why people can stand on a space sailing ship without falling off its deck and can stand on a spherical planet without falling off the bottom side. However it is not the scientific definition of gravity. Everybody in space has its own gravity. 
Gravity is an accommodating force in that its direction seems to be "that which is most convenient." In an object the size of a planet, gravity is directed toward a point at the center of the sphere so that people can stand anywhere on the surface, and dropped objects fall perpendicular to the surface. In smaller objects, like spacecraft, gravity is not a central point but rather a plane which cuts horizontally through the object to the end of the air envelope. 
Gravity itself is conveniently an all-or-nothing proposition. Either it is there at full strength or it is not there at all (though there are exceptions to every rule, per DM discretion).
Significantly, this gravity plane is two-directional; it attracts from both top and bottom. A sailor can actually stand on the bottom of the ship's hull and move around as easily as if she was walking on deck. In this case, what was "down" on the deck is actually "up", back toward the plane of gravity that cuts through the ship. 
One of the stranger and more fanciful side effects of all this is that an object falling off the side of a Spelljammer can oscillate back and forth across the plane of gravity, falling first in one direction until it crosses the plane, then reversing direction and falling back across the plane again, and so on until something causes it to stop. 
To a person standing on the deck, the object appears to fall down, then up, then down, then up, and so forth. 
This trick is commonly used to amuse passengers new to space travel. More than one groundling has gotten in trouble for standing at the ship's rail and tossing an endless stream of apples overboard just to watch them bob.
Along the plane an object is weightless, but it is slowly pushed out toward the edge of the gravity field. Therefore, a creature that falls overboard that couldn't find a hold or isn't tied down, would eventually come to rest at the ship's plane of gravity, and would then begin drifting away from the ship along that plane toward the edge of the air envelope. 
On reaching the end of the gravity plane (at the very edge of the air envelope) she is pushed out and left behind as the ship moves away. This movement takes place at a rate of 5 feet per round.
Aside from this slight push, there is no relative motion of a ship within its air envelope, aside from turning. A ship's air envelope does not turn with the ship when it turns, but objects in the ship's air envelope do not drift toward the rear of the ship simply because the ship is moving forward.
When gravity planes intersect (such as when two ships pass each other, or when a ship passes a planetoid), the gravities of both ships remain in effect, regardless of size, up to the point where they physically intersect. An object is under the influence of whichever gravity plane it is closest to. A character could leap between two passing ships, altering her down direction as she crosses the midpoint between the two.
When two ships come into direct contact, the gravity of the ship with the higher tonnage is dominant and becomes the gravity for both ships. A large mind flayer vessel could ram a smaller ship from directly above and spin the smaller ship's gravity plane by 90 degrees, causing everything on the rammed ship to tumble toward the large ship's plane of gravity, probably with disastrous results.
A weightless character who enters the air envelope of a larger body is immediately affected by the pull of gravity on that body. She effectively falls the distance from where she entered to the surface of the body or to the gravity plane, whichever is closer. Normal falling damage is applied, as well as massive damage rules. When the drop is more than one mile, there is also danger of the subject heating up and igniting from friction with the air. This happens after one mile of uncontrolled descent. The falling object catches fire and takes normal damage from fire as well as falling damage. Any sort of control over speed and descent (flight, levitation, feather fall, etc) negates this effect.
Characters who are weightless can move under familiar laws of physics - For every action, there is an equal and opposite reaction. A drifting fighter may move by throwing her equipment in the opposite direction. Max movement is half-speed when acting this way. Combat in a weightless environment is difficult and foreign to creatures used to fighting in normal environments, and any attack roll or saving throw using STR, DEX, or CON is made at disadvantage.
=== Air in Space ===
As stated prior All objects not only have their own gravity but they also drag air with them whenever they leave an air envelope. While important, air is relatively easy to replenish. Entering a larger air envelope like that of a planet or asteroid is one of the most popular and cheapest methods. Green plants will refresh air, and some vessels make great use of these for just this purpose. Many asteroid colonies keep at least half their surface area reserved for plants for this reason.
Air around a ship remains fresh for eight months with 50% of the max crew or less. With 51% - 100% of the max crew, air lasts for four months. 101% - 150% of the max crew, and air lasts for three months. 151% - 200% of the max crew, and air lasts for 2 months. More than double the crew cannot fit on a ship, due to sleeping and space requirements. Air cannot be extended by losing crew members mid-travel, but can be shortened by adding crew members mid-travel.
For example:
A 30 ton frigate sets sail with 30 crew aboard (including the party), the maximum crew size for that vessel. It has air sufficient for four months. After a week in space, 16 crew members are lost in a large space battle, making a total crew of 14. Even though this represents less than 50% of the max crew, it has no effect on air supply because air supply can’t be extended mid-travel. Two weeks later, if the same 30-ton frigate rescues 34 characters from a drifting hulk of a vessel, bound together and limping along. This raises the current crew to 50. This brings the total crew count greater than the max of 30. Air supply is reduced to three months, so the air will gain the fouled condition at the end of three months in space.
Any lone Medium-sized creature in Wildspace or the Phlogiston drags along with them enough air to last 5 minutes. Large-sized creatures (ogres and giants, for example) drag along enough air to last 10 minutes. If a medium-sized creature is standing on a rock 100 cubic yards in size it may have enough air to survive several months, but food and water is another matter entirely.
Fresh air is completely breathable. When a body reaches its air limit, the air gains the Fouled condition; it smells bad and is stale and humid. All attacks, checks, and saving throws in a fouled atmosphere are rolled at disadvantage. 
The time for air with the fouled condition is the same time during which it stayed fresh, effectively resetting the timer, after which it gains the Deadly condition. Deadly air is completely depleted. It cannot support life that breathes air. This happens the turn after the fouled air supply timer has run out. 
A creature can hold its breath for a number of minutes equal to 1 + its Constitution modifier (min. 30 seconds). When a creature runs out of breath, it can survive for a number of rounds equal to its Constitution modifier (min. 1 round). After this, the creature falls unconscious and is dying.
A creature falling unconscious in this way in the Phlogiston is put into suspended animation until such time as they are found or their body is destroyed, whichever comes first. Their flesh turns gray and stonelike and remains that way until the individual is rescued. 
Some races do excellent business in robbing and enslaving the unfortunate individuals they find adrift in the depths of Phlogiston.
When two bodies meet in space, their atmosphere is exchanged. The class of air (Fresh or Fouled) in the body that is smaller becomes that of the larger body. If the smaller body is at least 50% of the tonnage of the larger, both get one half as much air as the larger had remaining. If the smaller is less than 50% the size of the larger, both get the larger of two’s full supply of air, minus one week. The same rules apply for individual creatures, except on the smaller scale.
Creatures that do not breathe (undead, golems, etc) are unaffected by the status of the air envelopes but still carry the envelopes and exchange air. The envelope still depletes as normal.
Enroute to Nekhemra, the Verithian Merchant Galleon Parzival runs into a playful flock of Solar Albatross
==Space Travel==
Space travel is hard to grasp by most groundlings. They look up at the skies and see a vast emptiness of infinite beauty.
Spelljamming ships can be made of anything: normal, Space Faring galleons; gargantuan, mutated bodies of Beholders; Elven Sailing ships grown in a vast forest-turned-dry-dock; bones of long-dead dragons festooned upon the Decks of Viking Star Barqs; the splinters and masts of defeated Vessels; or even the very mountains themselves such in the case of of Stoneholm.
In Endless Aetherium, ships tend to look like vessels from the Golden Age of Piracy, and they tend to reflect the cultures they Hail from. Prime Examples of the various Vessels of Endless Aetherium
* The Verithian Empire; with Star Galleon and Ships the Line, with their sails to the Flow and Gundecks primed and ready.
* The Nordmen of Midgard; With Longships, Osebergs, and Large Gokstaad War Barques… Fueled by thiers sails and magics of the Norse 
* The Polyyshar; Polyyharan ships are armored ironclad vessels, cumbersome but able to withstand small impacts and navigate safely through the asteroid belts of their home sphere, powered by strange arcane fuel but also the raw psionic Willpower of their crewman.
* The Serenan; Agile Catamaran-like  Craft, intune with the magics of their people… 
No matter the shape they take, What makes them a Spelljamming ship is the Spelljamming Helm, whether permanently bolted down, or temporarily there.
=== Spelljamming Helms ===
Ships travel through Wildspace by means of the Spelljamming Helm - a magical device which converts mystical energy into motive force; ie. the "push" that moves a Spelljamming ship. This allows rapid movement from planet to planet. Some of the specifics vary from race-to-race, and ship-to-ship; however, most ships are equipped with a magical device known as a Spelljamming Helm. While the helm provides the push forward, the crew provides the maneuvering, stopping, and docking.
A Helm can be made to look like almost anything: A lofty perch made of hard oak, with pillows in the seat and back, and topped with gold filigree; a sleek, futuristic chair made of obsidian and lined with purple silks; a large leaf, elegantly grown into position and automatically shaping to fit it's user; a meditation bench, as simplistic in style as it is in make; or a large uncomfortable iron throne constructed from the swords of a defeated army. 
How a Helm looks will speak volumes about both its creator, as well as its user. All will function the same and provide the necessary focus point to move about space. Generally, it's installed onto the quarterdeck of a ship, in some cases away from prying eyes and (more importantly) attacks.
There are many sorts of basic Spelljammer Helms: Minor and Major. All Helms require the user’s Concentration to function, as if the user were concentrating on a spell. Due to the Concentration required, no more than eight hours can be spent at a time using this device by one caster. Attempts to "push through" may cause one point of exhaustion (as per the rules for a forced march in chapter 8 of the Player's Handbook).
==== Other sorts of rare or advanced Helms include: ====
* Lifejammers - These cruel helms suck the very life from the user to power a vessel and perform special maneuvers.
* Orbus - Mutated, Misshapen and specially grown Beholder-kin, used by the various Beholder races to provide movement to their strange and otherworldly vessels.
* Forgehelms - This device is installed in a ship’s core and provides the force necessary for movement throughout space without a helmsman. This does require a forgemaster and a portion of the crew forging to ensure proper upkeep and use of the forge itself. As this doubles as a blacksmiths forge for creating weapons and armor, a certain output of those forge-created items is needed in order to keep the fire burning and the ship moving forward. 
* Arcane Furnace - These magical constructs use the energies within a magic item by burning Magic items like fuel it confers a ship with motive power.
* Artifurnce - a priceless treasure in itself, functioning similarly to an Arcane Furnace, but instead uses the unrelenting power of an artifact and siphons it’s unlimited power to fuel a vessel indefinitely.
* Sequence Helms - This helm type allows for multiple characters to contribute to the overall Speed of a vessel, but halves a single user's contribution to the overall Ships speed. Helm Rating - detailed on the next page - is calculated normally, then halved, rounded down. The number of Sequence helms able to contribute to the ship speed on a single vessel is unlimited.
* Series Helm - strange aberrant helms, invented by the Illithids that utilized their innate psychic energies to sail the Phlogiston. 
Rarer and otherwise legendary Helms allow casting while simultaneously piloting the ship, remote control of a ship, full movement about the vessel, and much more!
Any character may use a helm, though only one character may use a single helm at a time. Attunement to the helm requires a short rest to ensure that the adventurer understands how to concentrate properly and convert their innate magical energy into ship movement. It takes one action to activate, and one action to deactivate the Helm. 
Characters with the Spellcasting, Ki, and Pact Magic class features can use additional abilities of the helm, listed later in this document.
Exhausted characters attempting to use a Helm reduce the total Speed of the ship by the number of exhaustion points they have attained. 
After 48 continuous hours on the Helm, regardless of the ship's current Speed or the number of exhaustion points gained, the individual using the Helm will pass out and be unable to use the Helm again until they complete a Long Rest.
Additionally while on the Helm, the Helmsman can observe her surroundings normally, but also gains an awareness of the space around the ship. This awareness is equivalent to what would be gained by a lookout. As an action, you can see from any point in or on the ship until the start of your next turn, gaining the benefits of any special senses that the ship has. During this time, you are deaf and blind with regard to your own senses.
While using the Helm to power a ship, the adventurer is unable to cast a spell of 1st level or higher, and is considered restrained. The individual seated upon the Helm can talk and act normally, but cannot leave the Helm while the ship is in motion.
=== Determining Helm Rating ===
Use the table below to determine your Helm Rating to spellcaster level ratio when determining the ship's overall Speed when using a helm to pilot a ship. A Minor Helm grants a 1:3 ratio of Helm Rating to spellcaster level, and a Major Helm grants a 1:2 ratio of Helm Rating to spellcaster level. This is similar to determining your spell slots when multiclassing, but all classes are able to provide motive force when using a helm to pilot a ship (Players handbook p.163-164)
Add together all your levels in the Bard, Cleric, Druid, Sorcerer, Warlock, and Wizard classes, half your levels (rounded down) in the Paladin, Monk, Ranger, Mystic, and Artificer classes, and a third of the levels taken in Fighter or Rogue classes (rounded down) if you have the Eldritch Knight or the Arcane Trickster archetype. Characters with levels in classes that do not grant the Spellcasting, Pact Magic, Psionics, or Ki abilities divide by four (rounded down, a minimum of 1) to determine Helm Rating.
Example 1: A 10th level wizard using a Minor Helm will have a spellcaster level of 10, and that same character grants a Helm Rating of 3 to the overall ship speed.
Example 2: A character that has multiclassed a 5th-level bard and a 3rd-level barbarian will have a spellcaster level of 6, and that same character using a Major Helm will grant a Helm Rating of 3 to the overall Speed.
Example 3: A character that has multiclassed a 6th level warlock and an 8th level paladin will have a spellcaster level of 10, and that same character using a Major Helm will grant a Helm Rating of 5 to the overall Speed.
Helm Rating
Spellcaster Level	Minor Helm	Major Helm
1 - 3 	1 	1
4 - 5 	1 	2
6 - 7 	2 	3
8 	2 	4
9 	3 	4
10 - 11 	3 	5
12 - 13 	4 	6
14 	4 	7
15 	5 	7
16 - 17 	5 	8
18 - 19 	6 	9
20 	6 	10
==Ship Terminology==
Armor Class (AC)- Difficulty of hitting a ship and dealing damage to the ship when striking it.
Beam Length- This is the measurement of the widest part of the ship from port to starboard (left to right). Important when dealing with gravity and the air pocket that surrounds a ship.
Crew Min/Max- These two numbers indicate the minimum number of crew required to operate the ship and maximum occupancy of the ship before air reduction becomes an issue.
Damage Threshold (DT)- An object with a damage threshold has immunity to all damage unless it takes an amount of damage from a single attack or effect equal to or greater than it’s DT, in which case it takes damage as normal. Any damage that fails to meet or exceed the object’s damage threshold is considered superficial and doesn’t reduce the object’s hull points. All Ships and Siege Weapons are immune to Poison and Psychic damage. DM discretion is given for damage types more effective against a particular ship or in a particular situation.
Helm Type- This indicates what type of Spelljammer Helm can be used to run the ship. Most ships can be run off either a Major or Minor Helm, but others may require a special type of Helm.
Hull Points (HP)- Hull points for ships are identical to Hit Points for characters and monsters. They measure the amount of damage the ship can sustain before it is destroyed.
Keel Length- This is the length of the ship from fore to aft (front to back). Important when dealing with gravity and the air pocket that surrounds a ship.
Maneuverability Rating (MR)- Your ships ability to turn, accelerate, and maneuver with the ship alone. Takes into account sails, rigging, size, weight, and other aerodynamic capacities.
Standard Armaments- This is the amount and type of weaponry that can be installed on a ship. These Encompass the types of Cannons: Swivel gun, the 8-pound cannon, 12-pound cannon, pound cannon, 24-pound cannon, and the 32-pound Bombard
Tonnage- This is a measure of the physical displacement that a spelljamming ship takes up. For each ton, you can consider the ship taking up 300 cubic feet of space. This displacement influences the amount of breathable air surrounding a ship in wildspace, and 300 cubic feet of space allows one medium sized creature to comfortably breathe for four months. Lastly, tonnage is used in determining the dimensions of the ship itself, crew size, and cargo limit. This is not a measure of the ship's weight. The actual dimensions of the ship are unimportant.
Type/Name- This is the name or type of your Spelljammer ship.
Ship Weaponry 
Ships that ply the Phlogiston and wild space require a modicum of defense from the threats of the void and it’s denizens. These defences tend to take the form of Cannons, Cannons are available in a variety of sizes, from the small maneuverable guns found on the top deck to the heavy guns found on gundecks. Most cannons are made of cast iron, but older cannons are made from cast bronze. Cannons are described by the size of the cannonball they fire, ranging from the small 1-pounder swivel guns to the heavy 32-pounder guns found on the battlements of coastal fortresses. The larger the ship, the greater the quantity and size of its
cannons. 
Before it can be fired, all weapons must be loaded and aimed. A Load, Aim, and Fire action are done using one Ship Action taken by the Master at Arms
A Cannon Broadside can turn the tide of any battle and clear the path for Board and other combatants
=== Cannons ===
*Swivel Gun - A swivel gun (or patarero) is breech loaded with 1-pound balls of cast iron. It can be turned to attack nearly any target, but it is not recommended to fire across your own deck. Swivel guns are positioned on the top deck of a ship and can be moved around the deck with minimal effort. They can also be added to a longship’s bow. It takes one action to load the weapon and one action to aim and fire it. ¼ pound of Thuud powder is required to fire this weapon.
*8 Pound Cannon- This weapon uses Thuud powder to fire 8-pound balls of cast iron, and needs to be loaded and aimed before it can be fired. It takes one action to load the weapon, one action to aim, and one action to fire it. Two pounds of Thuud powder are required to fire this weapon.
*12 Pound Cannon- This weapon uses Thuud powder to fire 12-pound balls of cast iron, and needs to be loaded and aimed before it can be fired. It takes one action to load the weapon, one action to aim, and one action to fire it. Three pounds of Thuud powder are required to fire this weapon
*24 Pound Naval Gun- This large cannon is called a ship wrecker, and is found only on the largest ships or the battlements of fortresses. The weapon uses Thuud powder to fire 24-pound balls of cast iron, and needs to be loaded and aimed before it can be fired. It takes one action to load the weapon, one action to aim, and one action to fire it. Six pounds of Thuud powder are required to fire this weapon
*32 Pound Bombard- This massive cannon is found only on the battlements of fortresses and are too large to fit on even galleons. The weapon uses Thuud powder to fire 32-pound balls of cast iron, and needs to be loaded and aimed before it can be fired. It takes one action to load the weapon, one action to aim, and one action to fire it. Eight pounds of Thuud powder are required to fire this weapon
* Alchemist's Fire Projector- This device shoots a thin stream of flaming, explosive liquid. Though it can be devastating in combat, the Alchemist's Fire Projectors are not popular with ships that cross between the spheres because of the flammability of the Flow. In fact, Alchemist's Fire projectors are recipes for disaster in the Phlogiston. They are popular, however among crews that do not leave their spheres. In the atmosphere near a planetoid, the Alchemist's Fire Projector has a 150/600 ft range.
Alchemist's Fire- While some adventuring parties know this substance as a thorw-able flask of sticky, adhesive fluid, aboard a Spelljamming ship it is generally stored in stone casks (for use as alternate ammunition in catapults). Alchemist's Fire ignites when exposed to air. When a cask is catapulted onto an enemy deck, the stone jug breaks and immediately explodes, dealing 3d10 fire damage in a 15-foot radius sphere. Any creatures in the sphere may make a DC 14 Dex saving throw. On a success, the target suffers half damage. On a failure, creatures and any other objects in the sphere are now on fire. Also may ignite other jugs in burst radius.
* Ram- Mounted to the front of ships, a Ram consists of nothing more than a heavy log, shod in iron. There are several different types that can be mounted to the front of Spelljamming ships. A ship can only have one type of Ram installed at a time. A ship can be outfitted with a ram on its forward facing. A ship equipped with a ram ignores the damage for the first square of a solid object it enters, and all damage from ramming creatures or other objects (such as other ships). A ram can be added to a ship for 1,000 gp
** Piercing- A piercing ram is a long, sharp prow used to break open and break apart an enemy ship.
** Blunt- This is a flattened prow designed to inflict internal damage by shaking up the smaller ship.
** Grappling- The grappling ram incorporates one or more movable arms which attach themselves to an opponent's ship with blades or hooks after ramming, locking the ships together. This type of ram is very useful during boarding situations.
==The Crew==
A good crew is the lifeblood of a sailing vessel. A ship cannot sail without a crew, and a crew cannot sail without a ship. They are interlinked, cosmically. The best crews will make voyages pleasant for you and terrible for your enemies. A Spelljamming ship sailing without a crew will fly at half Speed, as the needed functions of turning the sails, operating the oars, or maintaining the ship itself will have to be done by the party members. All spelljamming ships have two crew numbers as listed in the chart on Spelljamming Ships and Equipment- The minimum needed to run the ship, and the max that the craft can hold without overloading it’s atmosphere. A crew's skill, experience, morale, and health are defined by its quality score. This score can affect a number of general ship activities, like the crew's ability to notice threats or contend with hazards. 
A crew starts with a quality score of +4, but that score varies over time, going as low as −10 and as high as +10. It decreases as a crew takes casualties, suffers hardship, or endures poor health. It increases if the crew enjoys high morale, has good healthcare, and receives fair leadership. 
Crews of different Quality Scores are divided into three classifications: Green, Trained, and Crack. 
Standard costs per crewman,per month are below:
Crew 	Quality Score 	Base Pay
Green 	2 gp a head per standard month	
Trained	4 gp a head per standard month	
Crack 	6 gp a head per standard month	
Additionally, crews going into hazardous situations normally demand an extra share of plunder to be divided among the crew.
A Crack crew grants the proficiency bonus of the First Mate/Captain to attacks with all weapons attached to the party’s ship. A Crack Crew Cannot be hired.
=== Mutiny ===
A poorly led or mistreated crew might turn against its officers. Once per day, if a crew's quality score is lower than 0, the captain must make a Charisma (Intimidation or Persuasion) check modified by the crew's quality score. If the check total is between 1 and 9, the crew's quality score decreases by 1.
If the check total is 0 or lower, the crew mutinies. They become hostile to the officers and might attempt to kill them, imprison them, or throw them overboard. The crew can be cowed into obedience through violence, combat, or offers of treasure or other rewards.
When the DM ends the mutiny, the crew's quality score increases by 1d4.
=== Shore Leave ===
Life aboard a ship is a constant wear on the crew. Spending time in port allows the crew to relax and regain its composure.
If a crew's quality score is 3 or lower, the score increases by 1 for each day the crew spends in port or ashore.
Generally, unless the ship they are on is about to be destroyed, no crew member will stray far from the safety of the ship, even when moored at the most hospitable dock.
Some crew members may stick around through thick and thin and develop personalities and traits of their own.
==Ships Officers==
Who does what aboard a sailing vessel, and when? What kind of jobs are available aboard beyond the able-bodied sailor? This section will give a brief look into the roles on a Spelljamming vessel. It is advised to establish a Station for everyone aboard the ship to keep the troops in line and the decks swabbed. In case of trouble, everyone knows their job and what to do.
=== Stations ===
On a Spelljamming ship, various Stations exist that can be filled by a player at your table. Some positions may overlap (The Quartermaster and Bosun could be the same person, for example) as an adventuring party may not be large enough to accommodate all positions. Additionally, multiple party members may fill the same role if they wish.
==== Captain ====
A keen mind, and cool head… these are the qualities of a competent Captain. In the Roiling rainbow sea these are often experienced sailors in their own right. The Captain is the one to give orders, but is wise enough to respect the needs and input of his crew. The best captains have high Intelligence and Charisma scores, as well as proficiency with Spelljamming vehicles and the Intimidation and Persuasion skills.
==== First Mate ====
The force of personality necessary to hold together an unruly bunch of scallywags, the First Mate handles the crew in the best of times and the worst of times. A First Mate's duties mainly entails overseeing all aspects of the crew,and Cargo, but importantly his role is to also keep the Captain in Check serving as their second. A first mate benefits from a high Charisma score, as well as proficiency with the Intimidation and Persuasion skills.
==== Bosun ====
The Bosun takes care of the repair and fitting out of the vessel, and examines whether it is sufficiently provided with ropes, pulleys, sails, and all the other rigging that is necessary for a voyage. When fires erupt on-board, the Bosun is the one to call. A good bosun has a high Strength score, as well as proficiency with carpenter's tools and the Athletics skill.
==== Master at Arms ====
The Master at Arms is in charge of maintaining and firing the weapons and ammunition aboard a Spelljamming ship. This included sifting the powder to keep it dry, ensuring the cannons and ordnance were kept free of rust, and that all weapons were kept in good repair. A knowledgeable Master at Arms was essential to the crew's safety and effective use of their weapons.
==== Helmsman ====
The Helmsman is in charge of navigating the ship through spaces unknown. This officer is, more often than not, the most able-bodied mage aboard a Spelljamming ship.
==== Quartermaster ====
While the Quartermaster is in charge of the day-to-day sailing of a vessel, the Quartermaster directs the course and looks after the maps, instruments necessary for navigation, and messages to other ships and docks. Though it's not required to know any magic to be a Quartermaster, often this position also exists as a Second for the Helmsman. A reliable quartermaster tends to have a high Wisdom score, as well as proficiency with navigator's tools and the Nature skill.
==== Surgeon ====
The Surgeon has the distinct privilege of keeping everyone alive and healthy aboard the ship. More often than not, the Surgeon performs operations and amputations with the same tools that the Shipwright uses to repair the ship. A capable surgeon benefits from a high Intelligence score, as well as proficiency with herbalism kits and the Medicine skill.
==== Cook ====
Let no one tell you otherwise, the cook is just as important to the running of a ship as much as the first mate.  A ship's cook manages the ship's supplies and drinking water as well as cooking with the limited ingredients aboard a ship to make meals. A skilled cook keeps the crew's morale in top shape, while a poor one drags down the entire crew's performance, and could threaten to strand a ship with little to no food or drinking water. A talented cook has a high Constitution score, as well as proficiency with brewer's supplies and cook's utensils.
==Ship Combat==
There are times when diplomacy comes to an end, and conflict begins. Most groundlings fight hand-to-hand with sword, shield, and magic; horse, army, and castle. This is not so in the depths of space, as there's no field in the field-of-battle, just airless void and the ships you see before you. Siege weaponry has adapted quite well to the depths of space, and is used quite effectively.
At the beginning of combat, you roll initiative for each ship rather than each party member. A ship rolls initiative using 
its Dexterity, and it uses its crew's quality score as a modifier to that roll.
On a ship's turn, the Officer Give orders to the Crew and take Officer Actions
If combat becomes hand-to-hand, roll for character initiative. A combat round lasts 1 minute (60 seconds) in ship-to-ship tactical combat. Hand-to-hand combat rounds last 6 seconds.
Some victors of extraplanetary combat will sift through the debris of broken ships for prisoners, slaves, and loot, while others will abandon them. It’s possible for survivors to lash up some of the vessels to create a Temporary ship to save themselves with a Helm and air pocket, but they must act quickly!
=== Officer Actions ===
During your ships turn, each character may perform one Officer Action pertaining to their role on the ship. After Officer Actions are resolved, each character may take one normal round of actions. If a character does not select a ship role, they may only take one normal round of combat actions, such as preparing spells, healing, using small ship weapons (if the vessel possesses them), you may use your turn to buff your allies, your ship, prepare for boarding, .
Officer Actions are declared at the beginning of the combat round, before individual combat actions, and take place simultaneously - If a ship doesn't have enough members to crew the siege weapons and repair damage, while also repelling invaders, then priorities will have to be decided. If no decision can be made, then nothing happens.
After Officer Actions are determined and executed, then each character may take one individual turn. Many ship actions are listed below for each station on a ship, but this is not an exhaustive list. Players are encouraged to think outside of the proverbial box and come up with new and unique solutions. DM's are encouraged to give leeway within reason.
The rule is that if a player can perform the action and explain how their described Ship Action would help the ship, crew, or situation in any way, and would reasonably take under 60 seconds, it can be considered their Ship Action for the turn.
Officer Actions and who may use them are including, but not limited to:
==== The Captain and First Mate ====
The Captain and Firstmate may order crew to specific spots on the ship to attack or defend in hand-to-hand combat, or to avoid incoming attacks. Instead of ordering crew to specific stations, the Captain and First Mate may Encourage or Threaten, Take Aim
* Encourage or Threaten - The First Mate gives a short speech to a specific group of crew members already assigned to a task (such as the crew assigned to one siege weapon, or the crew assigned to repairing damage in a specific area). This functions as having used the Help action for each member of that specific group, and lasts until the beginning of the next turn.
* Take Aim - As an action, the captain, first mate, or bosun directs the crew's firing, aiding in aiming one of the ship's weapons. Select one of the ship's weapons that is within 10 feet of the officer. It gains advantage on the next attack roll it makes before the end of the ship's next turn.
==== The Quartermaster ====
The Quartermaster may view any maps or activate other devices that the ship has installed on-board to identify threats or escape routes, target foes, and navigate hazards. The Quartermaster may instead make a Spyglass action.
* Spyglass - Quartermaster scans the enemy vessel to obtain one piece of information:
**Basic Information: Visible crew on the deck, size, and information about any flags or other pieces displayed by the vessel. A PC may need to roll an associated ability check to discern meaning out of their observation.
**Defenses: Tonnage, ship type, and current Hull Points (described in a general sense), or information about one weapon.
**Hail! - Through a series of flags, lights, or other means, the Quartermaster may attempt to hail or send any message to the oncoming vessel that could be sent in one minute.
==== The Helmsman ====
may move the vessel up to the ship's Speed. Additionally, the Helmsman may initiate one Stunt.
In addition to ordinary movement, a Helmsman can attempt Stunts with their ship. Several stunts affect your starship’s Armor Class (AC), weapon attacks, and Movement abilities. Listed below are several stunts that can be performed by all Helmsman, using properties of the helm.
* Ramming - The Helmsman may Ram another ship. Ships equipped with rams can inflict massive amounts of damage. When ramming, the attack modifier used is that of the Helmsman’s spell attack bonus. If a hit is scored, damage is equal to the damage of the ram. Ships which attempt to Ram vessels more than twice their size in tonnage Crash instead. The ship must move in a straight line at least three consecutive hex spaces to perform a Ramming Ship Action.
* Shearing - The Helmsman may Shear another ship. Ships equipped with rams may attempt to shear away the rigging of the opposing vessels. This is treated as a ram attack, except no damage is done to the opposing ship. Instead, for each successful shear attack, rigging, ships weapons, and even crew can be targeted. The ship must move in a straight line at least three consecutive hex spaces to perform a Shearing Ship Action.
* Crash - A truly desperate move, a Helmsman may intentionally crash her ship into the opposing vessel, creature, or planetary body. If a ship moves into the space occupied by a creature or an object, the ship might crash. A ship avoids crashing if the creature or object is at least two sizes smaller than it. When a ship crashes, it must immediately make a DC 10 Constitution saving throw. On a failed save, it takes damage to its hull based on the size of the creature or object it crashed into, as shown on the Crash Damage table. It also stops moving if the object or creature is one size smaller than it or larger. Otherwise the ship continues moving and the creature or object collided with moves to the nearest unoccupied space that isn't in the ship's path. At the DM's discretion, an object that is forced to move but is fixed in place is instead destroyed.
A creature struck by a ship must make a Dexterity saving throw with a DC equal to 10 + the ship's Strength modifier, taking damage based on the ship's size (as shown on the Crash Damage table) on a failed save, or half as much damage on a successful one.
Crash Damage	
Size 	Bludgeoning Damage
Small 	1d6
Medium 	1d10
Large 	4d10
Huge 	8d10
Gargantuan 	16d10
A successful Crash will cause immediate Spelljammer Shock Critical Hit to the Helmsman initiating this action, and the target ship.
* Tactical Regroup
**Standard Major or Minor Helm - Expend One Level 1 (or higher) Spell Slot
**Lifejammer - Deal 1d8 Psychic damage to all Helmsman
**Prakhmiran Helm - Placeholder
The ship moves up to half its speed in the direction of the aft (rear) edge without changing hex facing. This action does not count towards the overall movement of the ship that turns, and uses no Speed.
* Barrel Roll
**Major or Minor Helm - Expend Two Level 2 (or higher) Spell Slots
**Lifejammer - Deal 2d8 Psychic damage to all Helmsman
**Prakhmiran Helm - Placeholder
The vessel moves up to half its Speed and flips along its central axis. Until your next turn, attacks made against your ship are made at disadvantage.
* Club Haul
**Major or Minor Helm - Expend Two Level 2 (or higher) Spell Slots
**Lifejammer - Deal 2d8 Psychic damage to all Helmsman
**Prakhmiran Helm - Placeholder
The ship moves forward up to half its Speed (without turning) and rotates 180 degrees to face the aft hex side at the end of the movement. This does not count toward Speed spent during the round.
* Turn in Place
**Major or Minor Helm - Expend Two Level 2 (or higher) Spell Slots
**Lifejammer - Deal 2d8 Psychic damage to all Helmsman
**Prakhmiran Helm - Placeholder
The ship does not move forward but instead can turn to face any direction. This does not count toward Speed spent during the round.
* Catch the Wind
**Major or Minor Helm - Expend Three Level 2 (or higher) Spell Slots
**Lifejammer - Deal 3d8 Psychic damage to all Helmsman
**Prakhmiran Helm - Placeholder
The ship moves forward one and a half times it's total Speed. The ship may not use any of this movement to change hex facings. The ship may not spend Speed to move during the round. If the ship has already moved, then this Stunt cannot be used.
* Flyby
**Major or Minor Helm - Expend Three Level 2 (or higher) Spell Slots
**Lifejammer - Deal 2d8 Psychic damage to all Helmsman
**Prakhmiran Helm - Placeholder
The ship moves as normal, but may move through 1 hex threatened by an enemy ship or creature without provoking an attack of opportunity.
==== The Master at Arms ====
may order crew to the siege weapons systems onboard to fire at enemy vessel(s). The Gunner may Fire Ship Weapons, Fire at Will, or Grapple.
* Firing Ship weapons - Weapons have “ranges” which are really the MR of their projectile. For example, the maximum range of a light catapult is 1,200 feet each round until it hits something or goes off into infinity. In planetary atmospheres the range is reduced to normal planetary ranges. A siege weapon attack includes loading and aiming the weapon. Some siege weapons like Catapults and Harpoons are mounted on rotating turrets. Cannons are mounted to their gun decks
* Broadside - The Gunner commands the crew to fire all siege weapons on-board at all enemy vessels. One attack is made per siege weapon, per target. These attacks are made at disadvantage.
* Grappling - This is a contested roll; Both ships participating in the grapple are required to roll 1d20 + Ship Speed. Degrappling is automatic if both vessels desire it, otherwise it’s resolved as a standard grappling roll. See Grappling on page 195 of the Players Handbook. Can only be used when targets are within one adjacent hex.
==== The Surgeon ====
The Surgeon may perform Medicine checks to diagnose wounds or diseases, create healing potions using an Herbalism Kit, administer healing potions to one group of crew members (such as the crew assigned to one siege weapon, or the crew assigned to repairing damage in a specific area), or cast healing spells. Additionally, the Surgeon may Mass Stabilize.
* Mass Stabilize - When this action is selected by the Surgeon during the Ship Action phase, you may stabilize any number of creatures on board that have been brought to zero. Those creatures remain in unconscious condition at 1 HP, and are prone.
==== The Bosun ====
The Bosun may order crew to repair damage to the vessel or it's weapons, put out fires, perform repairs herself, or cast spells that repair or bolster the defences of the ship. Additionally, the Bosun may perform a Brace for Impact and Douse Flames.
* Brace for Impact - When this action is selected by the Bosun during the Ship Action phase, any rolls on the Critical Hits table that target your ship are negated until the beginning of your ships next turn.
* Douse Flames - The Engineer triggers the flame retardant systems aboard the vessel. This Ship Action douses all flame aboard the ship including torces, candles, fires from explosions, and flame created by the Fire! Critical Hit.
=== Crew in Combat ===
Managing a ship's entire crew in combat can prove cumbersome, especially as larger ships often host dozens of sailors. Typically the crew is too busy managing the ship to do anything else during combat. Don't worry about tracking their specific positions unless you want to add that complexity. You can assume that the crew is evenly divided among the upper two decks of a ship.
==== Crew Casualties ====
Slaying a ship's crew reduces the number of actions most ships can take, making the crew a tempting target in combat. Resolve individual attacks as normal, using the guidelines for resolving many, identical attacks at once from the Dungeon Master's Guide as needed.
In the case of spells that cover an area, such as fireball or lightning bolt, you might track the exact location of the spell and crew to determine how many sailors it affects. Alternatively, you can roll 1d6 per level of the spell. The total of the dice is the number of crew members caught in the spell's area.
=== Critical Hits ===
Crewed siege weapons often have a chance of inflicting a Critical Hit to enemy vessels. Other events (Ramming, Spells, Crashing, turbulence from terrestrial or solar winds, etc) may also cause a Critical Hit. When a vessel is reduced to 50% of its Hull Points, it suffers a Critical Hit. When you score a critical hit, instead of rolling additional dice, you will roll on the following table:
==== Critical Hit Table ====
D10 roll	Effect
1 	Powder Magazine Compromised!
2 	Ship Shaken!
3 	Hull Holed!
4 	Temp -1d4 Speed loss for 1d4 rounds
5 	Gun Deck Stunned
6 	Deck crew Damage!
7 	Interior crew Damage!
8 	Temp -1d4 Speed loss for 1d4 rounds
9 	Fire!
10 	Spelljammer Shock!
Fire!- A fire starts somewhere in the ship, determined by the DM. If a fire is unable to start (all lights are magical, there is nothing flammable onboard, etc) then roll again.
Powder Magazine Compromised!-The Storage hold of the Alchemical Priming Powder stored in the ship’s Powder Magazine has been compromised, roll a d100 as this threatens the ship with a 30% chance of Catastrophic Arcane Explosion if the damage is not addressed immediately by the crew. The Duration to fortifying and repairing is 1d4 rounds during which only half of the ships armament can fire. If the Magazine detonates it deals 1d10 bludgeoning per 5 tons. This causes immediate Spelljammer Shock to the Helmsman/s
Ship Shaken- All PC’s not otherwise secured (Helmsman is considered secured) must make a DC 13 Dexterity saving throw or be knocked prone.
Hull Holed- The attack punches a sizable hole in the ship. DM decides location. If five total Hull Holed Critical Hits are scored on any vessel of 50 tonnes or less, it's internal structure is destroyed and the vessel starts to break apart. For vessels larger than 50 tonnes, the number of Hull Holed Critical Hits needed to break apart a vessel is 1 per 10 tonnes of the ship.
Deck crew Damage- One exposed creature is struck and suffers either the same damage as the ship or 2d10, whichever is higher. Choose the target randomly from all aboard the deck. All creatures within 5ft of that individual must make a DC 10 Dexterity saving throw or suffer the same damage.
Interior crew Damage- Same as a Deck crew Damage Critical Hit, but everyone not on deck is a potential target, including prisoners and Helmsman. This reflects not so much the missile itself, but shattered parts of the ship bouncing around during combat.
Gun Deck Stunned- The Shockwave of the Attacks has rattled the Gunnery Crew and thrown off their aim rendering them stunned until refocused. The Duration of Re-Aiming is 1d4 rounds. A Captain or First mate can reduce that time by ½ to a minimum of 1 with an Intimidation or Persuasion of DC of 10 or half of the damage the ship received. If no Cannons exist on-board the ship, roll again.
Speed Loss- The ship drops by the specified speed for 1d4 rounds (min 1). If a ship is already at Speed 1, then roll again.
Spelljammer Shock- The spelljamming Helmsman must make a Concentration Check (PHB p.203). If no damage was dealt to bring about a Critical Hit roll, then the DC is 10. If the Helmsman fails this check, they lose concentration and are unable to pilot the ship for 1d4 rounds, after which they are free to pilot again. In the case of multiple Helmsman, they all must make the save. In the case of Foundries, Artifurnaces, or other drives not using a Helmsman, the drive itself is rendered nonfunctional for 1d4 days while being repaired. If no replacement is available, the ship immediately becomes Speed 0 and can only move in a straight line at its present speed.
==== Breaking Apart ====
When a ship’s hull is reduced to 0 hit points it begins to break apart.
Roll a d6 for each 10 tons of ship to determine the amount of large atmosphere retaining piece breaks apart. Victors will usually sift through the wreckage for anything that can be salvaged (including Prisoners)
If the Player’s ship is breaking apart, each player must make a DC 15 dexterity save to determine whether they were able to cling to a piece of Atmosphere bearing debris, while those that fail drift away into open space. 
==== Towing ====
A ship can tow a vessel by grappling them as long as the opposing vessel has been rendered inert. Once grappled the towing ship’s speed is halved.
==Ship Travel Activities==
The activities available to a ship's crew and passengers are a bit different from the options available to a group traveling by land. Refer to "Activity While Traveling" in chapter 8 of the Player's Handbook for more information on some of the topics discussed below.
A number of activities are restricted to certain officers, unless the DM rules otherwise. For example, a DM might allow a bard to engage in the Raise Morale activity by playing bawdy songs on deck to lift the crew's spirits.
The party's pace has no effect on the activities they can engage in while traveling by ship.
Draw a Map
A ship's captain often undertakes this activity, producing a map of the ship's progress and helps the crew get back on course if they get lost. No ability check is required.
Forage
The character casts fishing lines, keeping an eye out for sources of food, making a Wisdom (Survival) check when the DM calls for it.
Raise Morale (First Mate Only)
The first mate can manage the crew's time to grant extended breaks, provide instruction, and generally improve the quality of life on the ship. Once every 24 hours, if the crew's quality score is 3 or lower, the first mate can make a DC 15 Charisma (Persuasion) check. On a successful check, the crew's quality score increases by 1.
Navigate (Quartermaster Only)
The quartermaster can try to prevent the ship from becoming lost, making a Wisdom (Survival) check when the DM calls for it. 
Noticing Threats
Use the passive Wisdom (Perception) score of the player characters or the crew to determine whether anyone on the ship notices a hidden threat. The crew has a passive Wisdom (Perception) score equal to 10 + the crew's quality score. The DM might decide that a threat can be noticed only by characters in a specific area of the ship. For example, only characters below deck might have a chance to hear or spot a creature hiding on board.
Repair (Bosun Only)
At the end of the day, the ship's bosun can make a Strength check using carpenter's tools. On a 15 or higher, each damaged component regains hit points equal to 1d6 + the crew's quality score (minimum of 1 hit point). A component other than the hull that had 0 hit points becomes functional again.
Stealth
The ship's crew can engage in this activity only if conditions restrict visibility, such as in heavy fog, darkness, etc. The ship makes a Dexterity check with a bonus equal to the crew's quality score to determine if it can hide.
=== Hazards ===
Sea travel is an innately dangerous proposition and Spellhaming is no different. A terrestrial storm might bog down a caravan, delaying its trip by a few days, while a storm in Wildspace or The Flow can be a nigh biblical event that can split even the mightiest warship in two and send everyone aboard to their doom. The close quarters of life aboard a ship leads to short tempers and brawls, while a few rats that sneak aboard can spread disease and spoil supplies. This section presents a variety of common hazards sailors might face on the sea.
==== Group Checks ====
To determine how a ship fares against these hazards, each threat requires the ship's officers and crew to make a special group check (see chapter 7 of the Player's Handbook for how group checks work). The description of a hazard specifies which officers can roll to contribute to the group check. That description also states what ability check an officer makes. Even if the officers make different ability checks, their successes and failures contribute to the one group check.
Additionally, all the non-officer members of the crew make a single check, a d20 roll modified by the crew's quality. The success or failure of all these checks—both the officers and the crew—determines the result of the group check.
While each hazard lists the officers assigned to participate in a group check, anyone can attempt an officer's check in a pinch, with two exceptions: First, only the captain can make checks associated with the captain's role; no one else can take the captain's place. Second, only one character can attempt an officer's check; they can't receive help.
Once all the checks related to the group check have been rolled, the ship's success or failure is determined. Hazards offer four levels of success or failure determined by the results of the ship's group check. A total success or a total failure occurs when every roll in the group check is a success or a failure, respectively.
==== Determining Hazards ====
Traveling by sea is an innately dangerous proposition. When running an ocean adventure, you can select hazards based on the needs of your campaign or generate them randomly.
To determine hazards at random, roll a d20 at the start of each day of a voyage. On a 20, the ship faces a hazard that day. Use the following two tables to determine the nature of the hazard and the DC of the threat it presents. Specifics corresponding to each of these DC levels are detailed along with each of the following hazards.
Hazard Type
d20 	Hazard Type
1-3 	Crew conflict
4-6 	Fire
7-9 	Fog
10-12	Infestation
13-20	Storm
Hazard DC
d20 	Hazard DC
1-9 	10
10-17	15
18-19	20
20 	25
===Crew Conflict===
Sailors can be a rough-and-tumble bunch, and cramming them into a ship's confined quarters leads to inevitable rivalries, feuds, and petty crimes. If resentments among the crew grow too strong, the officers must step in and set things right, lest they risk mutiny or worse.
Each day a ship spends dealing with a crew conflict requires those aboard to make a group check. The check's DC is randomly determined or chosen from the Crew Conflicts DCs table. The captain, first mate, and cook each make an ability check, as shown on the Crew Conflict Checks table. This check takes the place of any other activities that the officer might undertake that day, representing their contribution to placating the crew. If no one makes the check for a particular officer, a failure is contributed toward the group check.
Even though the crew is causing trouble, some members help the officers, and thus the crew still contributes a roll to the group check. Roll a d20 for the crew, using its quality score as a modifier to the roll, and compare that check to the DC.
Determine how many of the group's checks succeeded—the officers' and the crew's—then consult the Crew Conflict Check Results table.
Crew Conflict DCs
DC	Description
10	Minor scuffle or petty theft
15	Brawl involving several people, theft of a valuable
20	Large brawl resulting in several injuries, theft of a prized item
25	Murder, serious brawl involving most of the crew
Crew Conflict Checks
Officer 	Check
Captain 	Charisma (Intimidation)
First mate	Charisma (Intimidation)
Cook 	Intelligence (brewer's supplies)
Crew Conflict Check Results
Result 	Effect
Total Success	The crew's quality score increases by 1 for 1d4 days and the hazard ends.
Success 	The hazard ends.
Failure 	The crew's quality score decreases by 1.
Total Failure	The crew's quality score decreases by 1, and the crew immediately mutinies.
=== Fog ===
Fog on land is usually an inconvenience, but at sea it can prove disastrous. Decreased visibility makes navigation more difficult and can cause a vessel to crash.
A group check determines how the officers and crew manage through one day of fog. The check's DC is randomly determined or chosen from the Fog DCs table. The captain and quartermaster each make an ability check, as shown on the Fog Checks table. If no one makes the check for a particular officer, a failure is contributed toward the group check. Also, roll a d20 for the crew, using its quality score as a modifier to the roll, and compare that check to the DC.
Determine how many of the group's checks succeeded—the officers' and the crew's—then consult the Fog Check Results table.
Fog DCs
DC	Description
10	Light fog
15	Moderate fog
20	Heavy fog
25	Very heavy fog
Fog Checks
Officer 	Check
Captain 	Intelligence (water vehicles)
Quartermaster	Wisdom (Nature)
Fog Check Results
Result 	Effect
Total Success	The fog has no effect on navigation, and the crew's quality increases by 1 for 1d3 days.
Success 	The fog has no effect on navigation.
Failure 	The fog slows the ship, reducing its travel pace and speed by half for the day.
Total Failure	The fog slows the ship and disorients the crew, reducing the vessel's travel pace and speed by half for the day and causing it to move in a random direction.
=== Infestation ===
Provisioning a sea journey is challenging, particularly when allocating what to pack for the voyage. A rat infestation or an outbreak of even a minor illness can spell disaster at sea. This type of hazard covers illnesses, infestations, spoiled supplies, and other troubles that wear away a crew's health.
Each day a ship spends dealing with an infestation requires those aboard to make a group check. The check's DC is randomly determined or chosen from the Infestation DCs table. The captain, first mate, surgeon, and cook each make an ability check, as shown on the Infestation Checks table. This check takes the place of any other activities that the officer might undertake that day. If no one makes the check for a particular officer, a failure is contributed toward the group check. Also, roll a d20 for the crew, using its quality score as a modifier to the roll, and compare that check to the DC.
Determine how many of the group's checks succeeded—the officers' and the crew's—then consult the Infestation Check Results table.
Infestation DCs
DC	Description
10	Minor bug or rat infestation, common cold
15	Persistent bug or rat infestation, stomach ailment or typical flu
20	Serious bug or rat infestation, contagious flu or spoiled food
25	Overwhelming bug or rat infestation, lethal plague
Infestation Checks
Officer 	Check
Captain 	Intelligence/Wisdom (water vehicles)
First mate	Charisma (Persuasion)
Surgeon 	Intelligence (Medicine)
Cook 	Constitution (cook's utensils)
Infestation Check Results
Result 	Effect
Total Success	The crew's quality score increases by 1 for 1d4 days, and the hazard ends.
Success 	The hazard ends
Failure 	The crew's quality score decreases by 1.
Total Failure	The crew's quality score decreases by 1, and the distraction caused by the crisis forces the ship to move at half speed that day.
=== Storm ===
Winds and towering waves toss ships like bath toys. Snowstorms batter vessels venturing too far north. Hurricanes consume whole armadas. More common and deadlier than most sea monsters, storms claim more ships than any other threat on the high seas.
Each day a ship spends involved in a storm requires those aboard to make a group check. The check's DC is randomly determined or chosen from the Storm DCs table. The captain, first mate, bosun, and quartermaster each make an ability check, as shown on the Storm Checks table. This check takes the place of any other activities that the officer might undertake that day, representing their contribution to keeping the ship afloat. If no one makes the check for a particular officer, a failure is contributed toward the group check. Also, roll a d20 for the crew, using its quality score as a modifier to the roll, and compare that check to the DC.
Determine how many of the group's checks succeeded—the officers' and the crew's—then consult the Storm Check Results table.
Storm DCs
DC	Description
10	Heavy gale
15	Strong storm
20	Typical hurricane
25	Overwhelming hurricane
Storm Checks
Officer 	Check
Captain 	Intelligence (water vehicles)
First mate 	Charisma (Intimidation)
Bosun 	Strength (carpenter's tools)
Quartermaster	Wisdom (Nature)
Storm Check Results
Result 	Effect
Total Success	The ship survives unscathed. The crew's quality score increases by 1 for 1d4 days.
Success 	The ship survives unscathed.
Failure 	The ship's components each take 4d10 bludgeoning damage. The crew's quality score decreases by 1. The ship struggles, moving at half speed that day.
Total Failure	The ship's components each take 10d10 bludgeoning damage. The crew's quality score decreases by 2, and 10 percent of the crew is washed overboard and lost. The ship is blown off course and struggles to recover its bearings, moving in a random direction