Flanking

Movement And Position

Flanking represents catching an enemy between two threats, forcing them to split their attention. When two allies bracket an enemy, both gain a bonus to attack rolls and Rogues can apply sneak attack damage. It is one of the most powerful tactical advantages in Pathfinder and the main reason positioning matters in every combat.

The Core Rule

You are flanking an enemy when all three of these are true:

  1. You and an ally are on opposite sides of the enemy — a straight line drawn from the center of your square to the center of your ally's square passes through opposite sides or opposite corners of the enemy's space.
  2. Both you and your ally threaten the enemy (i.e. each is in melee range with a weapon that threatens that square and is not helpless, stunned, etc.).
  3. The enemy is not immune to flanking (see below).

When flanking, both you and your ally gain a +2 flanking bonus to attack rolls against that enemy. This is a circumstance bonus.

Determining Opposite Sides

Draw an imaginary line from the center of your square to the center of your ally's square. If that line passes through opposite sides of the target's space, you are flanking. If it passes through opposite corners, you are also flanking — diagonal flanking is valid.

Flanking (valid)

  • North side and south side of the enemy
  • East side and west side
  • Northwest corner and southeast corner (diagonal)
  • Northeast corner and southwest corner (diagonal)

Not flanking (invalid)

  • Both allies on the same side (north and north)
  • Both allies on adjacent sides (north and east — line passes through a corner, not opposite sides)
  • Ally is not threatening (out of range, helpless, no melee weapon)

Large and larger enemies: the line must pass through opposite sides of the creature's entire space (which is multiple squares). Two allies can be further apart and still flank a Large or Huge creature. See Size & Reach for space dimensions.

What Flanking Grants

Benefit Who gets it
+2 to attack rolls Both flanking allies gain the bonus against the flanked enemy. It's a circumstance bonus and stacks with most other bonuses.
Sneak attack eligibility Any character with sneak attack (Rogue, Ninja, some archetypes) may add their sneak attack dice to damage when flanking. The target must not be immune to precision-based damage (undead, constructs, oozes, etc.).
Denied DEX to AC? No — flanking does not deny the target their DEX bonus to AC. Only being flat-footed, feinted against, or otherwise unaware does that. This is a common misconception.

What Negates Flanking

  • Improved Uncanny Dodge (Barbarian 5, Rogue 8, and others): the character cannot be flanked except by a Rogue of 4+ levels higher. This specifically prevents sneak attack via flanking from most sources.
  • No discernible anatomy: oozes and creatures without a clear front/back cannot be flanked. They are immune to flanking entirely.
  • All-around vision: some creatures (some outsiders, creatures with the all-around vision special quality) cannot be flanked because they perceive threats from every direction simultaneously.
  • Swarm subtype: swarms occupy their space uniformly and cannot be flanked.

Key Flanking Feats

These feats specifically enhance or expand flanking — good picks for any melee character who fights alongside allies.

Feat Effect
Outflank When you and an ally with this feat flank an enemy, your flanking bonus increases to +4. When either of you scores a critical hit against the flanked enemy, the other immediately gains an attack of opportunity against it.
Gang Up You are considered flanking an opponent whenever two or more of your allies threaten that opponent, even if you are not on the opposite side. This allows lone Rogues to sneak attack without needing exact positioning.
Pack Flanking When you and your animal companion both threaten an enemy, you are considered flanking it regardless of relative position. Requires Combat Expertise and a bonded animal companion.
Precise Strike When you and an ally with this feat flank an enemy, you each deal +1d6 precision damage on melee attacks. Does not stack with sneak attack.
Swift Aid Use Aid Another as a swift action. While not a flanking feat directly, it lets you set up flanking-compatible positioning faster.
Feats & Class Features — Live Database Coming Soon

This section will pull all feats, rogue talents, and class features that reference flanking directly from the compendium — Outflank, Gang Up, Improved Uncanny Dodge, Sneak Attack, and more, each linked to their detail pages.