Abilities can be reduced, temporarily, or even permanently, by Ability Damage. When an ability drops to 0, it cannot be lowered any further, and an effect takes place according to the following rules.
If an ability is reduced to 0 by temporary damage, the following effects apply, based on whether the ability is physical, mental, or social.
A temporary 0 score in a physical ability leaves the character physically disabled for the duration of the damage. The character is still aware, and can speak, although in a weakened state. This persists until the ability damage is healed or otherwise recovered.
A temporary 0 score in a mental ability knocks the character unconscious until the ability damage is removed or healed.
A temporary 0 score in a social ability causes the character to be withdrawn and unable to handle social situations. The character is treated as if temporarily insane until this ability damage is removed.
The consequences of scores being reduced to 0 temporarily are significantly more intense.
When a physical ability score is reduced to 0, the character’s body dies. Psions, Weavers, and some other character types may have Edges that allow them to separate their consciousness from their body, which may allow them to continue living in a different form.
When a mental ability score is reduced to 0, the character becomes brain dead, and so is killed.
When a social ability score is permanently reduced to 0, the character becomes catatonic and withdrawn. While not dead, the character becomes little more than an animal, and is no longer suitable for play.