Flat Footed

Conditions

A flat-footed creature has been caught off-guard and cannot react normally. It has not yet had a chance to act in combat, or has been otherwise denied its ability to dodge and react.

Effects

  • Loses its Dexterity bonus to AC (if any). A negative Dexterity modifier still applies.
  • Cannot make attacks of opportunity — unless the creature has the Combat Reflexes feat.
  • Flat-footed AC is calculated as: AC – Dex bonus (all other bonuses still apply).
Sneak attack and flat-footed. A rogue (or any creature with sneak attack) can deal sneak attack damage against a flat-footed target, since the target is denied its Dexterity bonus to AC. This is one of the most common ways sneak attack is triggered.

When Does Flat-Footed Apply?

  • Start of combat — all creatures are flat-footed until they have taken their first turn, unless a special ability (like Uncanny Dodge) prevents it.
  • Unaware of an attacker — a creature that cannot perceive its attacker (e.g., attacked from hiding or invisibility) is denied its Dex bonus.
  • Feinted — a successful Bluff check to feint in combat causes the target to lose its Dex bonus against the feinter's next attack.
  • Balancing or climbing — certain skill failures can cause a creature to lose its Dex bonus.

Ending the Condition

  • A creature is no longer flat-footed once it has taken its first turn in combat.
  • The Uncanny Dodge class feature (Barbarian, Rogue, and others) prevents a creature from being flat-footed at the start of combat.
  • Improved Uncanny Dodge also prevents higher-level rogues from flanking the creature to deny its Dex bonus.

Related Conditions

  • Blinded — a blinded creature also loses its Dex bonus to AC against all attackers.
  • Helpless — a helpless creature's Dex is treated as 0 (–5 penalty), which is even worse than simply losing the bonus.
  • Stunned / Cowering — both cause loss of Dex bonus in addition to their other effects.

Common Sources

The start of every combat round (before a creature acts); being attacked by an invisible creature; a successful Bluff feint; certain spells and abilities that deny Dexterity to AC specifically. Note that flat-footed is a defined condition — some abilities trigger only against flat-footed targets (not just "denied Dex"), so the distinction matters.