Rules FAQ How Do Opportunity Attacks Work In D&D 5E?

An often-misunderstood element of 5E D&D, opportunity attacks allow combatants to strike fleeing combatants before they can leave. An opportunity attack, generally, follows these rules:

• A creature provokes an opportunity attack when it moves out of your reach.
• It uses your reaction for the round.
• It allows you to make a single melee attack with a held weapon or unarmed strike.
• It does not benefit from features such as Extra Attack.
• You must be able to see the creature to make an opportunity attack.
• The attack takes place just before the creature leaves your reach.

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This is the part of a weekly series of articles by a team of designers answering D&D questions for beginners. Feel free to discuss the article and add your insights or comments!

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That first point, which tends to be the one that confuses people, means that if you have a reach of 5 feet (you probably do) and a hostile creature moves from a space within 5 feet of you to a space further than 5 feet from you, you can make an opportunity attack as it leaves the space.

An orc with 5' reach
opportunity attack triggered just before the dotted line is crossed​

Avoiding Opportunity Attacks​

There are a number of ways to avoid opportunity attacks. For example, if a creature takes the Disengage action, its movement doesn’t provoke opportunity attacks at all for the rest of the turn, meaning it can move freely through your reach without threat. Other features, such as the Mobile feat for players, and the Flyby trait on monsters, can allow creatures to avoid opportunity attacks without taking the Disengage action. Features that teleport, such as the misty step spell or the Shadow Step feature of the Way of Shadows Monk, never provoke attacks of opportunity either.

Forced movement also doesn’t provoke opportunity attacks. For example, if a thorn whip spell pulls you out of an ogre’s reach, or you freefall past the reach of a giant spider clinging to a nearby wall, those creatures would not make opportunity attacks against you.

On the other hand, if movement uses your action, reaction, or movement, it is not considered forced, and can provoke an opportunity attack normally. For example, if a dissonant whispers spell causes you to use your reaction to move, and that movement causes you to leave a creature’s reach, that creature would make an opportunity attack against you, even though you didn’t willingly undertake the movement; cruel world, ain’t it?

Reach and Opportunity Attacks​

The Equipment chapter in the Player’s Handbook notes that a weapon with the Reach property increases your reach by 5 feet for the sake of attacks with it, including opportunity attacks. This means that, if you’re wielding a halberd, for example, a hostile creature only provokes an opportunity attack from you when they move from a space within 10 feet of you to a space further than 10 feet from you. Counterintuitively, this means wielding a weapon with Reach may actually limit your options for opportunity attacks, in some cases!

An orc with 10' reach
opportunity attack triggered just before the dotted line is crossed​

Alternatively, if you were wielding a whip (which has the Reach property) in one hand and a dagger (no Reach property) in the other, a creature would provoke an opportunity attack from your dagger when moving from within 5 feet of you to a space more than 5 feet from you. It would also provoke an opportunity attack from your whip when moving from within 10 feet of you to a space more than 10 feet from you. Keep in mind, however, you still only have one reaction, meaning you couldn’t take both of these opportunity attacks.

Opportunity Attack Feats​

A few different feats interact with opportunity attacks, and are listed below. There are a number of class features that interact with them as well, but they come up far less commonly.

Mobile​

This feat foils opportunity attacks in a pretty unique way. With Mobile, when you make a melee attack against a creature, that creature can’t make opportunity attacks against you at all for the rest of your turn. And keep in mind, that’s not “hit” with an attack. You just have to try. This feat can even foil Sentinel, as you’re not using the Disengage action.

Polearm Master​

With the Polearm Master feat, so long as you’re wielding a glaive, halberd, pike, quarterstaff, or spear, you can make an opportunity attack with that weapon when a creature enters your reach with it. So, for example, if you’re equipped with a pike, a creature that moves from outside your reach into a space within 10 feet of you would immediately provoke an opportunity attack from that pike. Amusingly, a creature can avoid this attack by taking the “Disengage” action while moving toward you, and doing so will even bypass Sentinel (as Sentinel only allows you to make opportunity attacks on creatures who attempt to leave your reach by Disengaging). Still, it’s a great way to hold enemies at bay, and the closest thing D&D has to the classic “spear-wall” strategy.

Sentinel​

With the Sentinel feat, your opportunity attacks reduce a creature’s movement speed to 0 on a hit, and even the Disengage action doesn’t prevent you from making opportunity attacks on fleeing targets. Keep in mind this doesn’t prevent features like Flyby, or Legendary Actions that ignore opportunity attacks, from working, as they don’t involve the Disengage action. Furthermore, the special reaction you get from the third bullet point of this feat doesn’t count as an opportunity attack, meaning it doesn’t reduce the target’s speed. Still, pair this with Polearm Master and a polearm with Reach, and wish good luck to whomever wants to try and get past you.

War Caster​

Remember how I said above that an opportunity attack must be a weapon attack? The War Caster feat breaks that rule. With War Caster, you can replace an opportunity attack with a single spell, with a casting time of 1 action, which targets only that creature, such as shocking grasp or hold person. Devious trick, but remember that ranged spell attacks made within 5 feet of a hostile creature are at disadvantage, and the opportunity attack goes off as the creature moves, meaning spells like fire bolt will be harder to hit with if the creature’s moving from within 5 feet of you.

 

[clearstream]

Or War Caster, which allows casting a spell like hold person on an opportunity attack.

Fun fact: a level 4 moon druid can wildshape into a giant octopus, which has a grapple+restrain on attack and a 10' reach. With the mobile feat and a cast of longstrider, said octopus can hold it's breath and skitter around at 30' per round on land for an hour. This is somewhat useful, and also just plain hilarious to picture.

Sentinel octopus druid subclass, confirmed.

I really wanted that to be monk, but I guess it has to be druid unless we make giant octopus a playable monstrous race.

 

[MarkB]

Sentinel octopus druid subclass, confirmed.

I really wanted that to be monk, but I guess it has to be druid unless we make giant octopus a playable monstrous race.

 

[dalisprime]

It's not always about escaping completely, sometimes it's just to get into a more advantageous position. Moving away might mean that whoever you disengaged from has to consider taking an opportunity attack from your allies.

Well yes but @Puddles did just say they wish their players took the risk more often - one way to do that is to make the enemies also take the risk and pursue the escapees. Granted, if the group is built around enemy movement shut down then this is more difficult to execute but otherwise as the old saying goes "practice what you preach".

 

[el-remmen]

If each square on a grid is exactly 5ft, then 2 creatures with an empty square between them would be exactly 5ft apart (because the distance between them would be exactly 5ft), an attack has to target a creature within range. Being 5ft away from a point, means you are within 5ft of that point, thus a creature with a 5ft range would be able to target an enemy 2 squares away, (and a 10ft polearm, 3 squares away). This would also dictate when AOO trigger too. I understand people don’t play this way, but I thought it interesting all the same.

I think distance is measured from the center of the square not the edge. So the edge of a box a box away would be 7.5 feet away from that box, not five.

 

[GMMichael]

... because it's what that monster or NPC would do? How is it "slowing the game down" if you've chosen to use it in your campaign?

It slows the game down by being "often misunderstood," per the OP. I'd say remove the rule entirely, but you know that some PCs are going to want to use it (especially those who aren't comfortable with the Ready action or turn-based combat). As a reaction limited to a single melee attack, the OA is easy to forget, but could be a big hassle if the DM tries too hard to use it.

 

[teitan]

thanks for posting this, it certainly clarifies some things that have come up in my game.

 

[MarkB]

We did have one campaign where we'd missed the "no forced movement" rule and had two characters in the group with Lightning Lure and Grasping Vine. We had two glorious weeks of slaughtering foes by ping-ponging them back and forth past the melee characters before we realised the error.

 

[teitan]

OAs can also be confusing for players and DMs coming from 3.x-Pathfinder as they are almost the same in concept but executed in different ways.

 

[Fallen star]

I wouldn't call it dangerous. D&D characters can defend all day long without using an action, and there is this Disengage action...

Great article! I'd add a protip: DMs should avoid making opportunity attacks for NPCs - why slow the game down for an optional, clunky rule?

It takes me about 3 seconds to roll an attack. It usually takes players about 3 minutes to decide whether or not to move.

 

[TheIceQueer]

To your point, I think Cassandra's line, "It uses your reaction for the turn" should read, "it uses your reaction for the round".

Super fun article!

Good point. Edited, because most people are not playing Mariliths!