From Worms Knowledge Base
/rubber[0 - 255]
- Bouncing worms
The original purpose of RubberWorm. Every time a worm hits an object or the terrain (in any direction), it bounces off of it. If it's during a rope roll, it can continue roping, and it never takes fall damage or loses the turn. The feature is always off if the worm is flying for a jump.
The worms' "boing" sound can switched on/off typing in the in-game chat /boing.
The value determines the worm bounciness (or technically, the coefficient of restitution). If the value is set to 0, the coefficient of restitution is 0, resulting in no bounce. If 255, the coefficient is 1, resulting in a perfectly elastic collision (the worm bounces with the same speed with which it hit the object or terrain).
/gravity[-64 - 63]
- Gravity modifications
Gravity can be made stronger or weaker, eliminated or even reversed. When reversed, a worm can stand on its head and shoot, but walking is obviously buggy. Also, should an object encounter no obstacle and fall into the sky, it will be sent to water when it reaches a certain height, otherwise it would block the game indefinitely.
The value controls the strength of gravity, from -64 to +63 in two's complement format (the seventh bit is the sign bit); a value of 0 or 12 results in default gravity (i.e. same as +12).