Opportunity Attacks in D&D 5e: Everything You Need to Know

The opportunity attack is the mechanic that catches every new D&D player off guard. Literally. You try to move away from the bugbear to go help your ally, and suddenly the bugbear's club is in your face because you broke a rule you didn't know existed.

This guide covers what opportunity attacks are, when they trigger, how to avoid them, and how to use them yourself to control the battlefield.

The Core Rule

When you move out of a hostile creature's reach, they can use their reaction to make one melee attack against you.

Key terms:

• Reach. The distance a creature's melee attack can cover. Usually 5 feet, but some creatures (ogres, some humanoids with reach weapons) have 10 feet.
• Reaction. A creature can take one reaction per round. Opportunity attacks consume the reaction.
• Move out of reach. Specifically, leave the area they can attack. Moving within the reach doesn't trigger. Stepping out does.

When Opportunity Attacks Trigger

• Willingly leaving reach. Moving out via your movement.
• Being forced out counts as movement in some rulings. If you're pushed out by a spell or ability, it depends on the DM. The AI follows the rules as written (forced movement doesn't usually trigger opportunity attacks, per 5e RAW).
• Standing up from prone and moving away. Standing doesn't trigger. Moving does.

When Opportunity Attacks Don't Trigger

• Moving within reach. Shifting from one adjacent square to another, still adjacent, doesn't provoke.
• When the enemy is incapacitated. Stunned, unconscious, charmed (sometimes), and other conditions prevent opportunity attacks.
• The Disengage action. Your entire turn's movement doesn't provoke.
• Using an ability that specifies "without provoking." Rogue Cunning Action (Disengage), Monk Step of the Wind, certain spells.
• Being invisible from the attacker's perspective. The enemy can't opportunity attack what they can't see.
• Teleporting. Teleport spells (Misty Step, Dimension Door) don't provoke. Teleportation counts as disappearing and reappearing, not moving through space.

How to Move Without Provoking

The Disengage action. Use your action to Disengage. Your entire turn's movement doesn't provoke opportunity attacks. Costs your action for the turn.

Rogue Cunning Action. Disengage as a bonus action. Keeps your action free for attack.

Monk Step of the Wind. Disengage as a bonus action for 1 ki point.

Teleport. Misty Step, Dimension Door, some Cleric and Sorcerer teleport spells.

Throw yourself to the ground first. No, this doesn't help. Going prone is free, but standing up to move still counts as movement. Net, no.

Grapple and drag. If you grapple the enemy, you can both move together. But if you stop being in their reach, technically you're leaving their space. Ruling varies. Generally safe to drag them with you.

Stay put. Sometimes the best move is not moving. If opportunity attack damage is bad, staying in melee and attacking is better than running and getting hit.

Using Opportunity Attacks on Enemies

You also get opportunity attacks when enemies try to leave your reach.

Position to threaten space. A Polearm Master fighter with a glaive threatens creatures entering AND leaving their 10-foot reach. Dense opportunity attack zone.

Sentinel feat. Opportunity attack hits reduce the target's speed to 0. They can't move further.

Polearm Master feat. Opportunity attack triggers when enemies enter your reach (not just leave).

Reaction timing. You only get one opportunity attack per round (one reaction). If two enemies try to leave, you pick one.

Class Features That Interact

Rogue Cunning Action. Disengage, Dash, or Hide as a bonus action. Best mobility feature in the game.

Monk Step of the Wind. Disengage or Dash as a bonus action for 1 ki.

Barbarian. No innate opportunity attack bypass. But Fast Movement at level 5 gives +10 ft speed, so you can cover more ground even when taking an opportunity attack.

Fighter Battle Master. Multiple maneuvers modify movement interactions.

Paladin Compelled Duel. Disadvantage on attacks that target anyone other than you. Keeps the enemy engaged.

Cavalier fighter (non-SRD). Opportunity attack-like features.

Common Misconceptions

"Moving through a creature's reach triggers opportunity attacks." No. Leaving reach does. Passing through and staying in reach doesn't.

"Opportunity attacks use my full action." No. They use a reaction.

"Two creatures can both opportunity attack me if I run past them." Yes, each creature gets one reaction per round. If you leave two different creatures' reach, both can opportunity attack you (one reaction each).

"Standing up from prone triggers opportunity attacks." No. Standing up costs half your movement, but standing itself isn't leaving reach. Only moving away after standing triggers.

The Endlessness and Opportunity Attacks

Our AI Dungeon Master tracks reach, reactions, and opportunity attack triggers automatically. When you declare "I move to the other side of the room," the AI checks for adjacent hostile creatures and their reach, triggers opportunity attacks where appropriate, and rolls.

The Disengage action, Cunning Action, Step of the Wind, and feat interactions (Sentinel, Polearm Master) all apply correctly.

For related reads, our action economy guide explains reactions in depth, and combat rules covers the wider movement system.

Final Takeaway

Opportunity attacks reward positioning. Choose where to stand carefully, know your escape options (Disengage, Cunning Action, teleport), and watch for enemies that can threaten big reaches.

Play a character who uses them well (Polearm Master Fighter, Sentinel Paladin), or one who bypasses them (Rogue, Monk), and combat becomes strategic.

Ready to try it? Start a character on The Endlessness and see how much moving smart matters.