Flat-Footed
At the start of a combat, if you are surprised, you are flat-footed until you become aware of combat and have had a chance to act. Many other effects can cause you to become flat-footed. You take a -2 penalty to your AC and cannot take reactions while flat-footed.
Source
Core Rulebook pg. 276
Dragonscript
Effect
bonus -2 to [character.kac, character.eac] as misc;