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.

 

[dalisprime]

Yeah, well, that's another fairly lame interpretation from the Sage because it means you can't try to grab, trip, or knock down someone who tries to run past you. All you can do is injure them and that's terrible from a tactical/narrative point of view.

It's all nice and well until you consider that DM controlled characters (monsters in particular) rarely have proficiency in athletics/acrobatics giving serious battlefield control advantage to players...I do not think players need any more of an advantage than they already have. You want to keep someone from running away, just grapple them on your turn, or take Sentinel/Warcaster (and any one of many movement inhibiting spells).
It also helps keep the game simple(ish). Rather than forcing the player to consider a range of options outside their turn it asks a simple yes/no question of: do you attack the retreating enemy.

 

[cbwjm]

Something I've never quite understood is the sentinel feat. Say they trigger the opportunity attack, you hit and reduce their movement. Does that mean they stop before or after crossing that dotted line? Like, will they still be adjacent or will there be a 5 foot gap between you and the target?

 

[Pax Drowana]

Something I've never quite understood is the sentinel feat. Say they trigger the opportunity attack, you hit and reduce their movement. Does that mean they stop before or after crossing that dotted line? Like, will they still be adjacent or will there be a 5 foot gap between you and the target?

In most cases, yes, they will still be adjacent to you.
From the definition of Opportunity Attack: "The Attack occurs right before the creature leaves your reach." (emphasis mine)
From the feat: "Whenever you hit a creature with an opportunity attack, its speed drops to 0 for the rest of the turn. This stops any movement they may have been taking."

If you have reach, however, the movement stops just inside the edge of your reach. For instance, in the halberd example in the article, the creature stops just inside the 10ft. reach.

This can lead to some ridiculous effects. A roper's tendrils, for example, have a reach of 50 feet, meaning you could run 100 feet from one end of the Roper's reach to the other, and assuming you avoided coming within the 5 foot reach of its bite, you wouldn't provoke an opportunity attack.

 

[Stormonu]

Another thing to consider is that if you are in a creature's reach, you can move around inside its reach (say if the DM allows bonuses for flanking) without triggering opportunity attacks.

However, you have to be careful - if you get caught between two or more areas of reach and leave EITHER, whichever one you leave gets to use its reaction to make an opportunity attack. That could mean multiple opportunity attacks, coming from different creatures. It makes getting surrounded quite dangerous and difficult to disengage.

 

[cbwjm]

In most cases, yes, they will still be adjacent to you.
From the definition of Opportunity Attack: "The Attack occurs right before the creature leaves your reach." (emphasis mine)
From the feat: "Whenever you hit a creature with an opportunity attack, its speed drops to 0 for the rest of the turn. This stops any movement they may have been taking."

If you have reach, however, the movement stops just inside the edge of your reach. For instance, in the halberd example in the article, the creature stops just inside the 10ft. reach.

This can lead to some ridiculous effects. A roper's tendrils, for example, have a reach of 50 feet, meaning you could run 100 feet from one end of the Roper's reach to the other, and assuming you avoided coming within the 5 foot reach of its bite, you wouldn't provoke an opportunity attack.

Thanks. I think I've read up on opportunity attacks a few times but I either missed that bit or it just didn't click in my head. I've been having trouble visualising sentinel for quite some time.

 

[dalisprime]

Honestly Sentinel in particular could do with a size related restriction. The gnome wizard stopping a tarrasque from moving with a dagger has become a meme for this particular reason.

 

[MarkB]

Honestly Sentinel in particular could do with a size related restriction. The gnome wizard stopping a tarrasque from moving with a dagger has become a meme for this particular reason.

Hey, any gnome wizard who's prepared to go toe-to-toe with a tarrasque is clearly a foe worth paying attention to.

 

[clearstream]

Yeah, well, that's another fairly lame interpretation from the Sage because it means you can't try to grab, trip, or knock down someone who tries to run past you. All you can do is injure them and that's terrible from a tactical/narrative point of view.

The RAW is clear on it being an Attack action (it has the words Attack action in the special melee attacks text). I wonder if there is a way to get around it? Some way a grapple can be attached to something that isn't an Attack action? Tavern Brawler puts it on a bonus action, but I can't think of anything that puts it on a reaction. Can you?

 

[MarkB]

EDIT: Nevermind.

 

[LizardWizard]

5e rules regarding opportunity attacks are the simplest ever, yet somehow we have to explain them 7 years into this edition...