© Wizards of the Coast by Irina Nordsol

Mage Slayer Feat DnD 5e: The Best Counterspell is a Big Sword

The doors to the temple chamber slam shut, cutting off the heroes’ escape. Hands glowing with purple electricity, the cultists of Vecna close in from all sides.

Standing between the grim-faced cleric and the nervous wizard, a human paladin grips her longsword and recites the sacred oath of her order. A cultist steps forward, a spell of shocking grasp crackling from his fingertips. 

Faster than the eye can follow, the paladin’s sword flashes through the air and the cultist falls back, screaming in pain and clutching a bloodied stump. Lady Altana the Mage Slayer locks her eyes on the high priest and gestures with her blade.

“You’re next.”

The Mage Slayer Feat provides an interesting – if somewhat situational – way to turn your character into the ultimate wizard hunter. While this feat isn’t for every class, or even every campaign, in the right context it can be a devastatingly powerful pickup and is undeniably one of the most narratively evocative feats in the game. 

Why Become A Mage Slayer? 

Whether your character belongs to an ancient order of cult-hunting paladins, has sworn bitter vengeance against an evil sorcerer king, or is an assassin who specializes in taking down troublesome wizards, Mage Slayer is an essential feat for anyone who wants to establish themself as a scourge of casters everywhere. 

Mage Slayer

You have practiced techniques in melee combat against spellcasters, gaining the following benefits.

When a creature within 5 feet of you casts a spell, you can use your reaction to make a melee weapon attack against that creature.

When you damage a creature that is concentrating on a spell, that creature has disadvantage on the saving throw it makes to maintain its concentration.

You have advantage on saving throws against spells cast by creatures within 5 feet of you.

Source: Player’s Handbook

Now, first of all, it’s worth admitting that, if you’re playing in a low magic setting, or know for some other reason that you won’t be encountering many spellcasters, this probably isn’t the feat for you. 

However, I think this feat gets underestimated in terms of its effectiveness. While Mage Slayer sometimes gets dismissed as being overly situational, the benefits that this feat confers aren’t actually restricted to fighting wizards like evokers and abjurers, warlocks, sorcerers, and other spell-slinging humanoids. 

The rules state that when any creature within 5ft of you casts a spell, you not only get to use your reaction to make a melee weapon attack against them, but you also get advantage on saving throws against spells they cast. 

From a Green Slaad, to Rakshasa, Oni, Night Hags, and Cloud Giants, not to mention several demons, devils, and various high priests, there’s a whole cavalcade of monsters that have the ability to throw out spells outside the realm of the average mad wizard or necromancer.

Being able to better get to grips with them, dish out more damage per turn, break their concentration, and more effectively resist their magical effects can be a huge bonus. 

Being able to use your reaction to make a secondary attack against a spellcasting target is a great way to either increase your damage output against them or as a deterrent that might make them think twice about casting a spell this round.

Also, the instinct of any caster who finds themselves up close and personal with a Mage Slayer will be to move away, still provoking an attack of opportunity.

Then, unless that caster has the ability to fly, turn invisible, or has access to some other form of escape, they’re going to have to watch you charge straight across the battlefield towards them at the start of your next turn. 

Mage Slayer is one of the best ways that melee-focused classes can lock down and control spellcasters and particularly evasive monsters. 

However, it’s worth noting that the trigger for this feat is the moment when the creature casts a spell, not when they begin to cast it. Therefore, an enemy can still dish out their damage spell, or cast something to help them escape (like Misty Step) before you can land a blow.

The exception to this is obviously spells with prolonged durations that require concentration, which is where the second element of this feat comes into play. 

The second aspect of this feat is a useful edge when breaking concentration spells like Hold Person, Fly, or Polymorph, which can be devastating ways for enemies to take your allies out of the fight. 

Lastly, the ability to gain blanket advantage against all spell saving throws when you’re within 5ft of your opponent is a really nice buff to survivability that does a lot to help round out this feat. 

Getting the Most Out of Mage Slayer 

Because you only grain the benefits of Mage Slayer within 5ft of an enemy, this feat is going to struggle to feel impactful on any primarily spellcasting or ranged attack-focused class. Being a Mage Slayer is all about getting up in enemy spellcasters’ faces.

As such, you’re going to want to play a melee-focused class like a Fighter, Barbarian, Rogue, Monk, or Paladin. You could also probably make this work with a Hexblade Warlock, Ranger, or a Cleric as well. 

Whichever class you choose to apply this feat to, the main problem you’re going to have to overcome is actually getting into melee range with any mages you plan on slaying.

Spellcasters like to hide out behind a wall of meaty, heavily-armored frontline troops. The necromancer has their army of shambling zombies, the high priestess of Lolth has the elite drow warrior retinue; every evil spellcaster or monster with innate magical abilities is probably going to make an effort to either put something between you and them or stay at range while they pepper you with magical attacks. 

The best way to solve this issue is to play some kind of character that’s mobile enough to stay on top of even the most slippery spellcaster.  

Eladrin are great for this style of play, as they get innate access to teleportation abilities through their Fey Step. If going full fey elf doesn’t do it for you, you can pick up the Fey Touched feat from Tasha’s Cauldron of Everything, which gives you access to Misty Step and an extra divination spell. 

If you want to hunt invisible or disguised wizards and warlocks to the ends of the earth, and consider playing a Hexblade Warlock that picks up the Witch Sight invocation at 15th level for the ability to see the true form of any shapechanger or creature concealed by illusion or transmutation magic. Or just have the party’s Wizard cast true sight on you.  

Which Classes Should Take the Mage Slayer feat?

Any class that focuses on melee combat is a candidate for the Mage Slayer Feat. However, Rogues and Paladins are both particularly strong options.

Both classes have a way to increase the damage applied to their melee attacks using Sneak Attack and Divine Smite, respectively. Rogues in particular suffer from being permanently restricted to a single attack per turn, so the ability to make an extra one as a reaction (especially when you apply your insane Sneak Attack damage at later levels) is a huge advantage. 

The Champion Fighter and Hexblade Warlock (via their Hexblade’s Curse ability – which is another great way to focus all your attention on a single pesky spellcaster) can both deliver critical hits more easily, and more attacks mean more critical hits, so being able to potentially use your reaction to get off another attack against an enemy mage is going to be very useful. 

If you want to be absolutely certain you stay within melee range of an enemy caster, a great way to do this is to ensure you have more movement speed than anyone else on the battlefield. No class is better at outmaneuvering and outrunning the enemy than the Monk.

Also, any character with the ability to fly is much better positioned to stick to an enemy caster like glue, so an Aaracockra, for example, should be able to chase their spellcasting foes in three dimensions instead of just on the ground. 

Frequently Asked Questions

Is the Mage Slayer Feat good? 

In short, yes. Although external factors like a shortage of, well, mages to slay, or internal factors like a character build that doesn’t focus on melee combat or lacks mobility can make this a less than optimal choice, in the right hands, Mage Slayer is one of the most powerful feats in the game.

Gaining advantage on spell saves can give you the confidence to go toe to toe with scary spellcasters in the late game, and helps boost the number of attacks you can dish out per turn – which is particularly useful for lower level Fighters and Paladins – not to mention Rogues of any level. 

Can Mage Slayer stop a spell?

No. Any spell with an instantaneous effect is still cast; you make your melee attack as a reaction after it takes effect. However, if the spell requires concentration, you can immediately end its effect if the caster fails their concentration check (which they make at disadvantage) following your attack. 

At which level should I get Mage Slayer?

This depends. If being a hunter of wizards, or member of a knightly order that takes down evil warlocks, or something of that ilk is part of your core character concept, then I’d suggest playing a variant human and taking the Feat at 1st level (or using the rules for a Custom Origin in Tasha’s Cauldron of Everything and picking whatever race you like) or 4th.

However, if this is something you just want to pick up for the useful benefits, or maybe as part of your character’s personal arc later on in a campaign (I personally like to give out Feats as rewards to my players like you’d hand out magic items) then Mage Slayer really comes into its own at higher levels, particularly if you’re playing a Fighter, Barbarian, or other martial class that can start to feel underpowered at higher levels when fighting alongside or against spellcasters with the ability to remake the fabric of reality on a whim and you’re still stuck hitting things with an axe.