Vehicles, Variant (PSR Supplement)

---

Definition and Function

A vehicle is a physical creation (primarily of a mechanical nature) with its own movement as a core feature, and which commonly is used to transport creatures, material, or the like. A vehicle necessarily cannot be a creature, even it if takes the shape or general appearance of a creature. Vehicles require either an internal or external source of energy by which to achieve locomotion, such as a creature to pull it, a sail to catch the wind, or an internal engine to drive it forward.

Vehicles are divided based on their medium of locomotion. Some vehicles travel on or below the surface of land, some on or beneath the water, some among or above the clouds. Some vehicles are able to travel through multiple mediums, such as on land and on water, but they are only capable of traveling through terrains and under conditions which are detailed for that vehicle, unless leeway is afforded by your narrator.

Vehicles are further subdivided by their specific means of locomotion. For example, vehicles which use rails and wheels are both capable of traveling on land, but railed vehicles, like a sled, are better at traveling across snowy or otherwise slippery terrain while wheeled vehicles, such as a wagon, are better at traveling along roads and across terrain with good traction. Furthermore, the above vehicles may move as directed, but a tracked vehicle, such as a minecart, can only move along its set track.

Regardless of a vehicle's movement type, there are three factors to keep in mind.

• First is the vehicle's directional movement speed, or the maximum speed at which a vehicle can move in a straight line under ideal circumstances.
• Second is the vehicle's acceleration, or how quickly its speed can change. A vehicle's acceleration and deceleration rates are equal to each other unless otherwise specified.
• Third is the vehicle's rotational speed, or to what degree the vehicle can change direction in a given turn. A rotation of less than the vehicle's rotational speed can be accomplished safely under normal circumstances, but a rotation greater than the vehicle's rotational speed may require a roll of some variety to achieve. For example, a wagon that can normally achieve a 1/4 turn can safely achieve a 1/8th turn but will face difficulty in making a 1/2 turn, if it can be done at all.

Please note: an airborne, submersible, or burrowing vehicle may list a vertical speed and acceleration, separate from its directional movement speed and acceleration, which dictates how quickly it can move vertically without pitching the vehicle up or down.

Hauling

Unless specified otherwise, vehicles can be hauled by creatures whose size and hauling capacity match or exceed the vehicle. If the vehicle is not accomplishing locomotion on land, these creatures must have a movement speed in that medium (a swimming, flying, or burrowing speed) of at least half their terrestrial movement speed. Unless otherwise specified, a vehicle will have its maximum movement speed replaced by that of the slowest creature that is hauling it.

If a vehicle has a sinking condition, the creatures hauling the vehicle must meet or exceed the minimum speed required, or the vehicle will be slowed and it will sink/fall. Hauling creatures which are able to meet at least half of the minimum speed for the sinking condition, or which succeed an appropriate saving throw, may slow the vehicle's sinking/falling.

Crashes

A crash occurs when a vehicle encounters a solid object, be it land, a creature, another vehicle, etc. If the vehicle has AC and Hit Point values and the object it was struck by was used as an attack, perform damage calculations. A vehicle without AC and Hit Point values struck by an attack becomes damaged to the point that it cannot achieve its normal locomotion.

If the vehicle and the object it struck, or which which struck it, both have AC and Hit Points, your narrator may use the following function at their discretion:

• If the vehicle is larger than the opposing object, or if it is the same size but has an AC greater than the opposing object, it gains resistance to the damage of this crash.
• The size of the opposing object determines the damage die/dice used. For a Tiny object, use a d4. For a Small object, use a d8. For a medium object, use a d8. For a Large object, use a d12. For an object above Large size, use a D20.
• Calculate the directional movement speed the vehicle was moving at relative to the opposing object when they encountered each other. For each increment of 5 feet worth of speed (rounded down), roll the damage die once (if the relative speed was less than 5 feet per turn, no damage calculations are required). The vehicle and the opposing object take that amount of bludgeoning damage.
• If the damage taken by either the vehicle or the opposing object is greater than either's Hit Points (after taking damage resistance into account), the damage instead becomes the minimum amount required to reduce either the ship or the opposing object's Hit Points to 0. If the damage taken was 10 or greater, or the survivor's HP was reduced by 10% or more of its maximum value (whichever is higher), the survivor is Slowed until the end of its next turn.

If the vehicle has AC and Hit Point values and the object it was struck by, or which it struck, was not used as an attack, does not have AC or Hit Point values, and is at least two sizes smaller than the vehicle, no damage calculations are required; the object is destroyed and the vehicle is unharmed. If the opposing object is one size smaller than the vehicle or larger, your narrator may determine how damaged the opposing object is, and may use the following function at their discretion:

• The vehicle has resistance to the crash damage.
• The size of the opposing object determines the damage dice used. For a Tiny object, use a d4. For a Small object, use a d8. For a medium object, use a d8. For a Large object, use a d12. For an object above Large size, use a D20.
• Calculate the directional movement speed the vehicle was moving at relative to the opposing object when they encountered each other. For each increment of 10 feet worth of speed (rounded up), roll the damage die twice(if the relative speed was less than 5 feet per turn, no damage calculations are required).
• After each roll, subtract the relative speed by 10. The vehicle may perform a Constitution saving throw against a DC equal to its relative speed (for example, if the vehicle was moving at a relative speed of 25, the speed would be reduced to 20 after the first round of damage rolls so the DC for the save would be 15). On a fail, perform damage calculations again and subtract the relative speed by another 10. On a pass, damage calculations end.
• The vehicle takes that amount of bludgeoning damage (with resistance taken into account).

Crash Landing

A crash landing occurs when an aquatic vehicle crashes into solid land, or when an airborne vehicle crashes into water or onto land. Some aquatic and airborne vehicles can be beached or landed without harm, but some, especially larger vehicles, require special infrastructure to dock at safely.

An aquatic vehicle which crash lands onto land takes 1D6 bludgeoning damage for every 5 feet of movement speed it had on impact (rounded down).

An airborne vehicle which crash lands onto land takes fall damage equal to the distance it fell. The vehicle gains resistance if it lands in water, but it also gains a sinking condition while it remains in the water, with a minimum speed equal to half the vehicle's acceleration speed. The vehicle takes only half damage if its fall was slowed right before impact.

Sinking

A vehicle sinks when its buoyancy is no longer sufficient to maintain its current altitude. This applies to all vehicles, but is only relevant for vehicles which travel on land when they face certain types of difficult terrain, such as thick snow and mud, which impart the sinking condition. Aquatic and airborne vehicles, meanwhile, typically only risk sinking upon taking sufficient damage to gain the sinking condition.

For each sinking condition in effect that a terrestrial or aquatic vehicle is not meeting or exceeding the minimum speed required by those condition, the vehicle sinks by one degree on the end of its turn. The degrees by which a vehicle can sink depends upon its size.

• Small and smaller vehicles can endure 1d4+1 degrees of sinking before they are sunk. 1 degree of sinking leaves the vehicle slowed, 2 degrees leaves the vehicle unable to move.
• Medium vehicles can endure 1d4+3 degrees of sinking before they are sunk. 3 degrees of sinking leaves the vehicle Slowed, 5 degrees leaves the vehicle unable to move.
• Large vehicles can endure 1d6+5 degrees of sinking before they are sunk. 5 degrees of sinking leaves the vehicle Slowed, 9 degrees leaves the vehicle unable to move. Once, after 1d4 turns, the narrator may roll a Constitution saving throw for the vessel. On a pass the sinking has been halted.
• Huge vehicles can endure 2d6+6 degrees of sinking before they are sunk. 7 degrees of sinking leaves the vehicle Slowed, 14 degrees leaves the vehicle unable to move. Up to twice, once after 1d6 turns and another 1d6 turns after that, the narrator may roll a Constitution saving throw for the vessel. On a pass the sinking has been halted.
• Gargantuan vehicles can endure 5d6+5 degrees of sinking before they are sunk. 9 degrees of sinking leaves the vehicle Slowed, 25 degrees leaves the vehicle unable to move. Up to four times, 1d6 turns after sinking begins or after the last check of this type, the narrator may roll a Constitution saving throw for the vessel. On a pass the sinking has been halted.

Sinking, aka falling, works somewhat differently for airborne vehicles. For each instance of the sinking condition they have accumulated, they fall by 10 feet per turn. An airborne vehicle cannot fall by more than 10 feet per turn by the effect of the sinking condition. If an airborne vehicle is unable to stop falling, it will suffer a crash landing upon contact with the ground or water below it.

Vehicles which are no longer sinking must still recover. For terrestrial and aquatic vehicles, creatures may need to dig the vehicle out or bail water. For airborne vehicles, altitude must be regained.

Capsizing

Most vehicles must maintain a certain relative orientation to remain functional - aka the top faces up, the bottom faces down. Capsizing occurs when a vehicle is knocked on its side or upside-down. This may occur when an object larger than the vehicle collides with it, when one side of a vehicle becomes heavily damaged, or when certain environmental conditions occur, such as dangerously sloped terrain for terrestrial vehicles or dangerous crosswinds for airborne vehicles.

When a terrestrial vehicle is capsized:

• It and creatures on and inside it are surprised. Creatures on the outer faces of the vehicle must pass a Dexterity (Acrobatics) check or be knocked prone.
• It is prone and has its movement speed reduced to 0. It cannot move under its own power.
• It takes 1d20 bludgeoning damage.
• Creatures of the vehicle's size or larger, or creatures with a hauling capacity equal to the vehicle's size or larger, may set the vehicle upright on the success of a Strength (Athletics) check.

When an aquatic vehicle is capsized:

• It and creatures on and inside it are surprised. Creatures on the outer faces of the vehicle must pass a Dexterity (Acrobatics) check or be knocked prone.
• It is prone and has its movement speed reduced to 0. It cannot move under its own power.
• The ship gains 1 instance of the sinking condition for every size above Tiny it is (for example, a Medium vehicle gains 2 sinking conditions, and a Gargantuan vehicle gains 5). The minimum speed required for these sinking conditions is equal to the ship's normal directional movement speed.
• Creatures of the vehicle's size or larger, or creatures with a hauling capacity equal to the vehicle's size or larger, may set the vehicle upright on the success of a Strength (Athletics) check.

When an aquatic vehicle is capsized:

• It and creatures on and inside it are surprised. Creatures on the outer faces of the vehicle must pass a Dexterity (Acrobatics) check or fall off the vehicle.
• Its vertical movement speed increases to its maximum and now directs the vehicle in another direction, based on how far the vehicle rotated (if the vehicle is upside-down, it is propelled downwards).
• The vehicle may use its rotational speed to right itself.