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.
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.
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.
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!
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.
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 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.
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!