Attacks Of Opportunity

Action Economy

An attack of opportunity (AoO) is a free melee attack you can make against a foe who lets their guard down in a square you threaten. Most AoOs arise because a combatant moves carelessly or performs a distracting action — casting a spell, picking up an item — while an opponent stands ready nearby.

Threatened Squares

You threaten all squares you can reach with a melee weapon you are currently wielding. By default this is all squares adjacent to you (within 5 feet). A creature you threaten can provoke an AoO from you; a creature outside your reach cannot.

  • Unarmed / natural attacks: threaten adjacent squares unless you have a special reach ability.
  • Reach weapons (longspear, guisarme, etc.): threaten squares 10 feet away but not adjacent squares (5 ft.). Creatures that step right next to you are inside your reach and do not provoke from movement.
  • Large and larger creatures have an extended natural reach — a Large creature threatens 10 feet, Huge 15 feet, and so on. See Size, Space & Reach for the full table.
  • Ranged weapons do not threaten any squares. You cannot make an AoO with a bow, crossbow, or thrown weapon.

Actions That Provoke

Any action that is distracting or exposes you to attack while you are in a threatened square provokes an AoO from every threatening opponent (unless otherwise noted). Common provocations:

Action Notes
Cast a spell or use a spell-like ability Any spell with a casting time of 1 standard action or longer. You can avoid the AoO by succeeding on a Concentration check (DC 15 + spell level) to cast defensively.
Move out of a threatened square Only the first square you leave provokes — further movement through other threatened squares does not provoke additional AoOs in the same movement. Exception: the Withdraw full-round action makes the first square you leave safe.
Pick up an item Reaching down to retrieve a dropped or placed item from the ground.
Retrieve a stored item Digging through a pack, quiver, or pouch to find a specific item.
Load a crossbow or sling Light crossbow and sling: move action that provokes. Heavy and repeating crossbow: full-round action that provokes.
Sheathe a weapon Putting a weapon away is a move action that provokes. Drawing a weapon (with BAB +1) does not.
Stand up from prone Rising from the prone condition is a move action that provokes.
Attack with a ranged weapon in melee Firing or throwing while a foe threatens you provokes, even if the ranged attack itself hits.
Use a combat maneuver Bull Rush, Disarm, Grapple (initiating), Overrun, Reposition, Steal, Sunder, and Trip all provoke unless you have the Improved feat for that maneuver.
Stabilise a dying creature Using the Heal skill on an adjacent dying ally (DC 15 Heal check, standard action).
Use a skill with an extended focus time Disable Device, Use Magic Device (scroll/wand in some interpretations), and other skill uses that require careful attention in combat. Check the skill description.

Actions That Do Not Provoke

These common actions are safe to perform even while threatened:

Attack (melee, no movement)
Channel Energy
Dismiss a spell
Drop an item
Drop to prone voluntarily
Draw a weapon (BAB +1 or higher)
Swift or immediate actions
Total Defense
Feint (Bluff vs. Sense Motive)
Speak (free action)
5-foot step
Cease concentration on a spell

Making an Attack of Opportunity

When a foe in your threatened area triggers an AoO, you may immediately make one melee attack against them — even if it is not your turn. This attack:

  • Interrupts the provoking action. The AoO resolves first. If the provoking creature is killed or rendered incapable by the AoO, their action is wasted.
  • Uses your highest attack bonus — not an iterative attack penalty.
  • Counts against your AoO limit. You can normally make only one AoO per round regardless of how many creatures provoke. This limit resets at the start of your next turn.
  • Cannot itself provoke an AoO (making an AoO does not provoke a counter-AoO from the original attacker).
  • Requires you to be able to act. You cannot make AoOs while flat-footed, stunned, paralyzed, or otherwise unable to act.

Combat Reflexes

Combat Reflexes is the feat that removes the one-AoO-per-round limit.

  • You may make a number of additional AoOs per round equal to your DEX modifier (minimum 0).
  • Each AoO still requires a separate trigger and a separate foe (you can't make multiple AoOs against the same trigger event).
  • You may also make AoOs while flat-footed — a rare exception to the normal flat-footed restriction.
  • The additional AoOs from Combat Reflexes do not apply to readied attacks or other special actions — only to genuine attacks of opportunity.

Avoiding Attacks of Opportunity

Method How it works
Cast defensively Succeed on a Concentration check (DC 15 + spell level) to cast without provoking. Failure means the spell is still cast but you provoked; on a natural 1 the spell is also lost.
5-foot step Moving exactly 5 feet does not provoke — but only if you haven't otherwise moved this turn and the destination isn't difficult terrain. See Movement & Position.
Withdraw action The full-round Withdraw action makes the first square you leave safe — but subsequent squares in the movement still provoke normally.
Improved [maneuver] feat Each Improved combat maneuver feat (Improved Bull Rush, Improved Grapple, etc.) removes the AoO that maneuver would normally provoke.
Tumble (Acrobatics) Move through a threatened square without provoking by succeeding on an Acrobatics check (DC 15, or DC 20 + CMB if the threatening creature is larger than you).

Commonly forgotten: provoke rules

  • Running through multiple threatened squares — only the first square left provokes
  • Firing a ranged weapon into melee — always provokes
  • Using a combat maneuver without the Improved feat — always provokes
  • Channelling energy — does not provoke
  • Total Defense — does not provoke

AoO quick reference

  • 1 AoO/round (default) — or DEX-mod extra with Combat Reflexes
  • Highest attack bonus — never iterative penalty
  • Interrupts the provoking action
  • Cannot be made while flat-footed (unless Combat Reflexes)
  • Reach weapons threaten 10 ft. but not 5 ft.