Immunity
The creature takes no damage from the listed source. Creatures can be immune to certain types of damage, types of afflictions, conditions, spells (based on school, level, or save type), and other effects. A creature that is immune to critical hits doesn’t take double damage or suffer critical hit effects. A creature that is immune to a listed source doesn’t suffer from its effects or from any secondary effects that it would trigger.
Format: Immunities acid, paralysis.
Guidelines: A creature usually has one immunity, plus one for every 5 CR. Broad immunities such as immunity to mind‑affecting effects or all magic should be chosen with caution and might count as multiple abilities.
Source
Alien Archive pg. 155