Flat-Footed

Flat-Footed 

You’re distracted or otherwise unable to focus your full attention on defense. You take a –2 circumstance penalty to AC. Some effects give you the flat-footed condition only to certain creatures or against certain attacks. Others—especially conditions—can make you universally flat-footed against everything. If a rule doesn’t specify that the condition applies only to certain circumstances, it applies to all of them; for example, many effects simply say “The target is flat-footed.”

— Core Rulebook pg. 620 2.0