In D&D 5e, an Attack of Opportunity is essentially a free attack that your character can make against an enemy.
It’s hard to beat free!
When in combat, you will want to keep an eye out for chances to make an opportunity attack. With D&D’s roots as a tactical war game, these can quickly turn the tide of battle for better or worse.
So let’s dive in and talk about attacks of opportunity and how to use them!
What is an Attack of Opportunity?
As I mentioned, an Attack of Opportunity is effectively a free attack against an enemy.
When taking an opportunity attack, you use your reaction to make one melee attack against a provoking creature.
Ok, so it sounds simple enough, right?
Where players often get confused, however, is when figuring out what “provoking” actually means.
So let’s go over what does and does not provoke an attack of opportunity.
What Provokes an Attack of Opportunity?
A creature provokes an opportunity attack when they move out of an enemy’s reach.
This is typically when an enemy moves away from being within 5 feet of the attacker. On a battle grid, this means that they are attempting to move to a square that is not adjacent to your character.
The attack happens right as the creature is leaving your character’s reach.
All in all, there’s not a whole lot to say about what provokes an attack of opportunity. It’s a pretty straightforward mechanic.
But we need to also cover how you avoid falling victim to one of these attacks yourself!
How to Not Provoke an Attack of Opportunity
Of course, you will want to make sure that you don’t provoke an opportunity attack with your character’s movement as well.
So how do you avoid being on the less-fun side of this mechanic?
The best way to avoid provoking an attack of opportunity from an enemy creature is by taking the Disengage action. If the fight is going bad and you need to fall back, this is how you do it safely.
If you want to learn more about the Disengage action, check out our article on Actions and Combat.
Of course, you can also teleport to safely avoid an opportunity attack. This makes spells like Misty Step and Thunderstep particularly useful!
Some classes have abilities (like the Storm Sorcerer’s Tempestuous Magic feature) that also let them move without provoking an attack of opportunity.
Taking an Attack of Opportunity
Taking an attack of opportunity is simple enough on the surface: you use your reaction to make an attack against a fleeing enemy.
But it’s important to stay tactical in combat and mindful of your character’s action economy. Because this attack uses your reaction, it may not always be a wise decision to take advantage of an opening!
When You Should
Generally, you will almost always want to take an attack of opportunity against an enemy.
More often than not, a reasonably intelligent will provoke this when they are attempting to run away. Because they are probably beginning to run low on hit points, this could be the final blow!
When You Shouldn’t
So why wouldn’t you want to take an attack of opportunity?
As we mentioned, it comes down to your character’s action economy. Because you only get one reaction between turns, you might take your opportunity attack only to find that you then can’t use your reaction for something else.
For example, let’s say that your party is fighting a group of evil cultists.
Fearing for his life, the cultist that your Bladesinger Wizard been wailing on attempts to cut and run. You take your opportunity attack and slay him before he’s able to get away.
But now it’s the Cult Leader’s turn. He laughs as he points his finger and fires a Disintegrate spell at you. You have counterspell prepared, but you no longer have a reaction to use it this turn!
Trying to get out of the way of the spell, you fail your Dexterity saving throw and take 80 points of damage. As you are reduced to 0 hit points, the dust of your disintegrated body is carried away with the wind.
By using your reaction to eliminate the fleeing cultist, you left yourself with no defense against the boss’s spell!
Sometimes, it’s better to resist the temptation and stay strategic when an enemy provokes an opportunity attack…
Stay mindful of your abilities and which ones use your reaction before you take an attack of opportunity!
Helpful Feats To Consider
A few feats interact in some very interesting ways with attacks of opportunity.
It’s certainly worth considering these options if you find your character frequently getting opportunity attacks or would like them to get more.
Sentinel
Fittingly enough with the name of this feat, it’s hard to get past a sentinel!
All three of this feat’s abilities relate to taking opportunity attacks and even let you take them more often!
For starters, hitting an enemy with an opportunity attack reduces their speed to 0 for the rest of the turn. As they try to get away, you hit them so hard that they are unable to move further!
Secondly, even if the enemy uses the Disengage action, you can still make an attack against them!
Then comes the cherry on top: you can make an attack against an enemy who is near you but attacks someone else. (Note: Despite using your reaction, this is not an attack of opportunity.)
Yeah… the Sentinel feat is a beast!
War Caster
Among all of the benefits of the War Caster feat, the coolest is being able to use a spell as an attack of opportunity.
Rather than having your wizard take a swing with their staff or whatever they are wielding, you can instead use your reaction to fire off a spell that meets a couple of requirements.
The spell that you use must have a casting time of 1 action and target only the provoking creature.
So while you can’t use a big spell like Fireball, being able to hit them with something like Chromatic Orb or Magic Missile is a major step up!
Polearm Master
A character with the Polearm Master feat will have no shortage of chances to make an attack of opportunity.
Not only do they get the chance to smack an enemy when they are trying to flee, they also get to do so when the enemy creature enters their reach.
Combining this with a reach weapon like a halberd or glaive can be disgusting! If a creature enters or leaves the 10 feet around you, you can make an attack of opportunity!
A Few Rules to Know
There are few extra rules and tips that you should be aware of that relate to taking an attack of opportunity.
It Is One Attack
When making an attack of opportunity, it is one attack.
Abilities like Extra Attack or the Monk’s Flurry of Blows can’t be used here.
You Must Be Able to See the Creature
If you cannot see the creature that is moving out of your range, you do not get an opportunity attack. Being in a dark room without darkvision or the hostile creature turning invisible would both prevent you from being able to take a swing at the creature.
You can’t hit what you can’t see!
You Can Use Your Abilities
So while you can’t take multiple opportunity attacks against an enemy, that doesn’t mean that you can’t add a little razzle-dazzle!
An attack of opportunity is a great time to use abilities like the Monk’s Stunning Strike or the Paladin’s Divine Smite.
This is particularly useful if you’re fighting a boss who is trying to make a quick getaway. Because abilities like these are typically very powerful, you can potentially end the fight right then and there!
Forced Movement
Forced movement does not provoke an attack of opportunity.
An effect that moves a creature without using their movement, action, or reaction does not provoke an opportunity attack.
So spells like Thunderwave or an Eldritch Blast from a Warlock with the Repelling Blast Invocation that push an enemy away cannot be used to provoke opportunity attacks.
Conclusion – Attack of Opportunity in D&D 5e
There’s a special type of excitement when an enemy provokes an attack of opportunity in D&D 5e.
This mechanic adds a nice extra level of tactics to combat. Generally, you will very rarely want to pass on the chance to take advantage of an opportunity attack, but it’s wise to keep your eyes open. While this is a chance to land a decisive blow, you don’t want to find yourself in a situation where you wish you still had your reaction!
Still have questions about using opportunity attacks in D&D 5e? Let me know in the comments!
If two NPCs decided to flee, can you react on both?
Hi Sandro!
Taking an attack of opportunity uses your reaction. You only get 1 reaction until the start of your next turn so you’re only able to smack one of the creatures that are trying to get away.
If two creatures are looking like they’re about to try and make a run for it, you might want to prioritize the one that’s looking rougher so you can get the final blow on it! 🙂
Hope this helps!
That is what i was thinking. Thanks again.
This was good, but missed 2 big questions.
When do you get your first reaction? This was the one I was just reading. Unless you are surprised you get a reaction (and thus an OA) at the beginning of combat unless you are surprised. If you are surprised you don’t get a reaction until after your first turn.
The second big question is if you have a weapon with a 10ft reach at what point do you get an OA on someone leaving? Is it when they move one square away or 2 squares away? (Assuming standard 5ft squares.) I have not seen a satisfactory answer to this question.
Hi WOLF!
Attacks of Opportunity require your reaction. Each character in combat gets 1 reaction per turn. If you use your reaction, you cannot take another until it resets at the start of your next turn. A surprised character isn’t able to use their reaction.
Here’s a link to my article that covers the surprise mechanic in more detail! 🙂
https://tabletopjoab.com/what-is-surprise-in-dd-5e-and-how-does-it-work/
For your second question:
The specific trigger for an attack of opportunity is that a creature is moving out of your reach. More often than not, this is when they move out of 5ft range of you.
In the case of a weapon with Reach (like a halberd, for example), you’ve got 10 feet of reach. In this case, the creature would have to move out of your 10ft reach.
You can smack more people thanks to the reach of the weapon, but enemies get slightly more options for their movement when close to you without provoking an attack of opportunity. (Though taking the Polearm Master feat lets you hit them when they enter your range as well!)
Hope this helps! 🙂
Fun question, this literally just happened in my game. There was an enemy that was attempting to move and Sentinal was used to stop them. They were standing next to another PC. Then enemy just made a ranged attack at the original PC who used Sentinal. Would this allow the Other PC an Attack of opportunity as the NPC tried to move or does one not exist because they were prevented from moving.
Hi Matthew!
That is a fun question! To answer it fully, let’s look at the order of actions being taken.
Situation:
The enemy was next to two PCs (one of which has the Sentinel feat), attempted to move away (provoking two attacks of opportunity), was hit by the Sentinel PC, then made an attack.
In this case, the enemy provokes opportunity attacks from both of the PCs.
Even if the Sentinel PC takes their attack of opportunity first, it was the enemy *attempting* to move that provoked the opportunity attacks in the first place. This means that both PCs can take their opportunity attacks.
If the Sentinel PC connects, the enemy’s speed is reduced to 0. The enemy can still attack and does so without provoking another attack from the Sentinel PC (who used their reaction for the AoO.)
Elsewhere on the site it is mentioned that a character could use 1/2 movement to run 15 up to a creature, smack the creature a good one (RNG willing), then use remaining 1/2 of movement to run away. How would the Attack of Opportunity fit into this scenario? Thanks in advance.
Hi Claude!
If the smack is enough to reduce the creature to 0 hit points, they’re free to move wherever they would like.
If the character misses or doesn’t deal enough damage and tries to run away, the enemy creature would get an attack of opportunity as the character tries to leave its attack range! The character can still try to fall back (maybe back behind their allies) but it’s a bit riskier now! 🙂
War caster says that you can use a cantrip as an attack of opportunity. can you use said cantrip as written or does it change it into a single target spell for that casting, and if it does change it into a single target spell, then as a sorcerer can I use twin spell om it to attack a second target. (Example: Eldritch Blast) If used as written then with the casting I should be able to target multiple characters with this one attack of opportunity and if not due to an attack of opportunity rule that I am not aware of making it a single target spell then would twin spell apply.
this is due to a new concept of a warlock, sorcerer, polearm master concept that I am hashing out
Hi David!
That sounds like a cool concept!
For Eldritch Blast, you can use it to take an Attack of Opportunity but all of the beams must target the creature that is provoking the AoO.
As for Twinned Spell and War Caster, it gets pretty sticky. There’s a bit of conflict between that and War Caster. War Caster doesn’t let you cast a spell at anything other than the target that is provoking the AoO which would then conflict with Twinned Spell that allows you to target a second creature.
There seems to be no shortage of debate on exactly how this stack works, but the general consensus that I’ve found seems to be that it doesn’t.
https://rpg.stackexchange.com/questions/156521/can-the-twinned-spell-metamagic-be-used-on-a-spell-cast-as-a-reaction-from-the-w#:~:text=Twinned%20Spell%20allows%20you%20to,that%20provoked%20the%20opportunity%20attack.
I hope this helps! 🙂
using PAM, does the OPportunity attack allow the 2nd attack with the butt end of the polearm?
Hi Gordon!
Unfortunately, you only get one attack of opportunity.
You’re able to use your reaction to take the attack of opportunity, but the bonus action required to make the second attack with PAM can only happen on your turn!
Fortunately, PAM lets you smack enemies when they’re entering your range instead of having to count on them trying to leave that range without disengaging first!
Hope this helps! 🙂
The “cherry on top” for the sentinel feat is unfortunately not entirely correct. When an enemy attacks someone other than you, who doesn’t already have the feat, you don’t get an AoO against the enemy – it’s just a regular melee weapon attack.
This is important for a couple of mechanical reasons:
Hi Hecko!
Good catch and I appreciate you pointing that out! Article updated!
Magic missile very likely can’t be used for attacks of opportunity even with war caster because you can target more than one person with it by sending the missiles to more than just one target. (This also means I think your saying that Eldritch blast can’t be used.) Yes, I know that you can limit your attack to that, but in the meta magic rules, it clearly states that you can’t twin spell magic missile since you can attack more than one person so I’m using this as a reason to interoperate it as the spell must be incapable of targeting more than one person. The way Warcaster is written is slightly grey there and I can easily see both sides.
Hi Michael!
You’re correct and I could use a different example instead as far as strictly RAW goes.
In my own personal games, I allow my players to use spells like Eldritch Blast or Magic Missile when taking an opportunity attack with War Caster provided that they are only targeting the provoking creature.
As rare as those situations come up in my own games, that little house ruling snuck into the article as a force of habit by mistake. 😉