So, vehicles. They exist in Gamma World, but they’re poorly supported. Here’s a very rough sketch of how I might handle them in mine, if it came up:
– Vehicles have hit points (a given) and sometimes a resistance to physical damage. Size the hitpoints about how you might a monster of a level on par with the PCs current level. Resistances should be minor, and might convey onto the occupants (but not stack). Occupants of vehicles will in general have basic cover. A “bloodied” vehicle will need minor repairs after the encounter in order to function again. A vehicle reduced to zero hit points will immediately cease functioning and, if in motion at the time, crash. It may be totaled (reduced to negative bloodied value) or it may simply need major repairs to function again.
– Vehicles have a size, similar in intention and implementation to monster sizes, but might be narrower than they are wide. Size should refer to its longest dimension, so a 3-square-long (15′) vehicle would be Huge, etc.
– Vehicles act as mobile platforms that one or more creatures can occupy. They’re treated as difficult terrain in terms of moving onto them from the surrounding area, but movement inside in general should be treated as unimpeded (unless there are a lot of obstacles — seats, cargo, etc).
– Vehicles have a speed.
– One time this speed is considered “cruising”; two times this speed is “racing”.
– For a minor action on part of the driver, Speed can be temporarily boosted by a successful skill roll (Mechanics?) against a moderate target, adding two squares to the base speed of the vehicle for that round. Failing this roll reduces the base speed by two squares. (The increase/reduction reverses if the driver is trying to wrestle with the controls of an out-of-control speeding vehicle.)
– For a move action on the part of the driver, the driver can:
+ Increase the current speed from “stopped” to “cruising”
+ Increase the current speed from “cruising” to “racing”
+ Decrease the current speed from “cruising” to “stopped”
+ Decrease the current speed from “racing” to “cruising”
+ Turn the vehicle up to 90 degrees. (45 degrees — going from a perpendicular to diagonal direction or vice-versa — is also possible)
+ Make a (Mechanics?) roll to turn the vehicle more than 90 degrees. This is Moderate if the vehicle is currently cruising, Hard if the vehicle is currently racing.
+ Make a (Mechanics?) roll to take the vehicle from racing to stopped or vice-versa. Moderate difficulty.
+ If either roll is failed when attempted, the vehicle gains the Out Of Control condition (see below).
– Vehicles move a number of squares equal to their current speed at the end of the driver’s turn (or, if there’s no driver, at the end of the round).
– Crashes should be rated as doing damage as is level-appropriate for a low medium or high limited damage expression, with low/medium/high determined based on speed. Occupants that are not restrained will be pushed from the vehicle in a random (1d8 determines) direction equal to half the vehicle’s speed immediately prior to the crash. The vehicle takes damage from the crash as well.
OUT OF CONTROL (Condition)
– The vehicle can’t go slower than cruising
– All driver actions require a (Mechanics?) roll to succeed. Actions which would already require a roll are made at -2.
– If the driver makes a (Mechanics?) roll to control the vehicle, roll a d20. On a 10 or better, the vehicle loses the Out of Control condition.
– If the driver fails a (Mechanics?) roll to control the vehicle, roll 1d6:
1: The vehicle turns 45 degrees to the left
2: The vehicle turns 90 degrees to the left
3: The vehicle turns 45 degrees to the right
4: The vehicle turns 90 degrees to the right
5: The vehicle speed increases to racing if it isn’t already. If it is, the vehicle crashes.
6: The vehicle crashes.
