Negative level

Each negative level gives a creature a -2 penalty on attack rolls, saves, skill checks, ability checks. Also inflicts a -1 penalty to effective level (effects things like spells and abilities which rely on caster level or character level). Negative levels stack.

If the target has as many negative levels as its Hit Die or levels, it dies.

Negative levels regenerate at a rate of 1 level every 2 minutes.