Sleep Gas Generation

is a physical mutation that generates, which can cause other creatures to fall asleep. Creatures that have this mutation are also themselves immune to all sleep gas, including sleep gas generated by other hostile creatures. This immunity does not extend beyond gas (it won't prevent other forms of sleep).

In order to be affected by sleep gas, a creature must respire. Robots and holograms do not respire and cannot be affected by sleep gas.

Generating gas must be toggled on in the abilities menu. Upon choosing to generate gas, for each round that this mutation is active, the user releases a total density of 800 units of sleep gas, spread evenly into the open-air tiles surrounding the user. If some of the tiles surrounding the user are walls or other occluding objects, the sleep gas will be concentrated into a smaller number of cells at a higher density. Once toggled on, the ability cannot be turned off until it has finished generating gas for the full number of turns based on the current mutation's level. Released gas inherits the phase of its owner.

Creatures caught in sleep gas must succeed at a Toughness save or fall asleep for a certain number of rounds. The difficulty of the save and number of rounds of sleep are determined by the strength of the sleep gas (which is equal to mutation level).

Formulas
The following formulas are used to determine gas level and release duration based on mutation level.

Advancement Table
This table shows only the mutation duration (the number of rounds during which the user will release sleep gas) and the level of gas released.

For details about sleep gas Toughness saves and the duration of sleep, refer to the article.

Advantages

 * Can serve a defensive purpose as fairly powerful panic button.
 * Is quite powerful throughout the entire game, even if left at level 1.
 * Can serve an offensive purpose, as sleeping enemies suffer a large DV penalty and attacks against sleeping enemies get a bonus to penetration.
 * Grants immunity to sleep gas.
 * This does not make the player immune to falling asleep, just to the effects of sleep gas.
 * With high enough Willpower and a high enough mutation level, the player can produce sleep gas constantly or near-constantly.
 * Flying creatures will fall to the ground and be knocked prone.

Disadvantages

 * Enemies who do well enough on their Toughness save may resist the effects of the sleep gas.
 * Ineffective against ranged enemies, as the difficulty of the Toughness save generally drops off further away from the source of the sleep gas due to lower gas density.