War Caster 5E: DnD Feat Guide

There are some feats that are just always on the short lists of certain builds in D&D. Ranged weapons users will take Sharpshooter, trouble makers will take Fey Touched, and monks who don’t know what they’re doing will take Athlete over Mobile. For some reason. 5E’s War Caster feat is one of the premium feats for magic users and will be on the short list of every capable caster.

War Caster is one of the most popular feats in 5th Edition D&D because it gives casters advantage on concentration saves from Constitution saves, as well as granting the ability to use an offensive spell as a reaction for an opportunity attack as opposed to just a weapon strike.

So is war caster all it’s cracked up to be, or will a deep dive reveal cracks in its outer fa├žade? Let’s dive in to find out!

War Wizard caster – he’s all the prepped for battle.

Breaking Down the War Caster Feat

The first step to breaking down any 5th Edition Dungeons & Dragons feat is to look at the exact wording before breaking down the feat point by point, so here it is!

Directly from the Player’s Handbook:

Prerequisite: The ability to cast at least one spell

You have practiced casting spells in the midst of combat, learning techniques that grant you the following benefits:

  • You have advantage on Constitution saving throws that you make to maintain your concentration on a spell when you take damage.
  • You can perform the somatic components of spells even when you have weapons or a shield in one or both hands.
  • When a hostile creatures’ movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than make an opportunity attack. The spell must have a casting time of 1 action and must target only that creature.

The Player’s Handbook, p. 170

Let’s break down the War Caster feat benefit by benefit to see what all it has to offer.

Benefit #1: Advantage on Constitution saving throws that you make to maintain spell concentration when you take damage.

This is the major benefit of war caster. It’s one of two major feats that gives a strong benefit to casters who need to make concentration saves. Since many of the best spells in DnD are concentration spells, this alone is an outstanding option. Constitution saves are also difficult at any point, and giving spellcasters advantage is huge.

Especially in the early to mid-game where those Constitution scores might not be high enough to give much of a bonus to concentration checks/saves.

This is an outstanding feature and is worth taking the feat in and of itself.

Benefit #2: You can perform the somatic components of spells even when you have weapons or a shield or both in your hands.

From a RAW perspective this is important, but it also addresses a weird gray area that most DMs home ruled from day one. Generally martial classes don’t have to put down weapons/shields to cast, and casters don’t draw weapons but cast spells, then can draw as a free action once done.

I have yet to run into a DM who enforces this RAW, which could make combat mechanics in some situation very clunky, but if you do run into that this takes care of it. This can also make sure that an unconventional build like a sorcerer with a +2 shield can work without concern.

I feel like this really isn’t a benefit as the way DMs run games involve ignoring the RAW that are potential problems such as the ones this particular “benefit” addresses.

Benefit #3: When a hostile creature’s movement provokes an opportunity attack from you, you can cast a spell (cantrips included) rather than a weapon attack. The spell must have a target time of one action and ONLY target that one creature.

This is a weird one. On the surface, it’s an exceptional benefit, and I think anyone who sees it that way has a very defensible opinion. Being able to dive into the big bag of spells instead of doing a simple weapon attack can be huge whether a mixed casting class like ranger, a martial caster like cleric, or a specially built warlock.

This can be incredibly powerful, and a warlock with supercharged Eldritch Blast can cause serious problems here. But…

How often do opportunity attacks come up? Spellcasters are usually the ones enemies are charging for, so hostile creatures aren’t going to move past them or away from them, but right at them.

Stupid creatures will just charge into warlocks and clerics on the front line as opposed to past them, also eliminating another chance of an opportunity attack.

The benefit is extremely powerful and excellent…but real in-game situations make it probably far more situational than it appears at first glance.

5E Classes That Should Take the War Caster Feat

There are four classes that should always consider the war caster feat a high-priority target. These casting classes can always use the war caster feat and it offers benefits that are going to be a mainstay of making them epic-level casters, along with high ability scores and a specialized feat like spell sniper, metamagic adept, or others.

The full caster classes are all classes that should take the war caster feat.


Bards are all about battlefield control and then can be customized to secondarily add healing, damage, or a weird eclectic mix of all of it. There are several great bard spells that don’t require concentration – and many that do. Also for bards taking Magical Secrets, they might decide the best out of class spells for their build are spells that demand concentration.

Depending on the build the bard either wants to stay away from combat or might be threading the needle where they dive into combat but still need to be able to keep up concentration. With some very unique spells that target one enemy, it’s possible to argue that the bard can use war caster’s benefits in a versatile way above and beyond any other full casting class.


For a full caster like a sorcerer holding concentration on those spells is crucial. And in those situations where somehow a hostile creature closes the distance, a sorcerer doesn’t wat to resort to a dagger in the off-chance it moves past them to a wizard or tries to retreat.

War caster is one of the must-have feats for casters and that definitely includes sorcerers.


Warlocks should definitely be taking war caster. Beefier than sorcerers, and most wizards, and often seen as a secondary threat to other casters in the class, they have a unique combination of combat and magic skills that let them slip under the radar, putting that using a spell as an attack of opportunity as arguably the best part of the feature for them.

Keeping in mind there are several melee-based warlock builds now, and the stunning power that a powered up Eldritch Blast can inflict, war caster is an outstanding powerful feat that every 5E warlock should take.

Imagine an enemy trying to bypass you to attack the wizard, and not only hitting him in the chest with three beams from an Eldritch Blast, but shoving him backwards 30 feet while doing it.

A very handy situation.


Wizards are the casting class, and with more concentration spells than any other class, and entire sub-classes that depend on the ability to keep up concentration.

War caster + spell sniper is a combo I’ve seen very few successful wizards without.

When you look at “battle wizard” sub-classes like the blade singer, then this feat makes even more sense as it gives a lot more options in combat when dealing with enemies passing through your zone of control. Imagine a buffy pack alpha watching you swing a blade at another pack member, then when it passes you to go after the squishy sorcerer taking a disintegrate to the chest off a reaction.

5th Ed Classes that should always take the War Caster Feat:

  • Bards
  • Sorcerers
  • Warlocks
  • Wizards

5E Classes That Should Consider Taking the War Caster Feat

These are all classes that can make very good use of war caster, although they have enough other things going on that the war caster feat isn’t necessarily a “must have” versus a “excellent idea for a viable build.”


Partial casters who may want to concentrate on a spell while their created companions do their thing, artificers come in so many flavors that plenty of their builds could do with a boost from the War Caster feat.


Clerics are one of those classes with so many good builds, and so many hats, that they show up a lot in this middle section for fats that an entire build could be done around. Clerics can be very effective when using the war caster feat, and for killer blender cleric builds, having that advantage on concentration saves for the few hits that get through to them can be huge.

There are many great concentration-based cleric spells, and the ability to unleash hell with a powerful spell when an enemy is trying to move past you towards the back line makes this a great feat that can really pull its weight with a variety of different cleric builds.


Many Druids spend a lot of time in wild shape as opposed to humanoid form as a full-time caster among the party. So it takes a very focused Druid to make the biggest use of this particular caster feat, but for the right Druid who has reasons to be light on the use of shape change this feat might have some interesting benefits.

5th Ed Classes that should consider taking the War Caster Feat:

  • Artificers
  • Clerics
  • Druids

5E Classes That Should NEVER Take the War Caster Feat

For traditional non-casting classes like Barbarians, Fighters, Monks, and Rogues, it makes sense why this feat wouldn’t make a blip on the radar. This is thoroughly a caster’s feat, after all.

Paladins don’t need this even with the benefit of using a spell as a reaction because paladins are all about the smite. They need their melee weapon attack anyway since they can wait to see a hit before choosing to use the smite spell they would use to pile on the damage anyway. Since Paladin buffs aren’t concentration based, there’s just not much reason for them to take this feat.

Rangers are one of those partial casting classes that don’t have enough concentration spells for this to make sense, and are using feats either for archery/distance fighting or if they are a rare melee Ranger, then the class needs even more help to buff themselves up. There just isn’t enough practical value in-game to make this a necessary take.

5th Ed classes that should never take the War Caster Feat:

  • Barbarians
  • Fighters
  • Monks
  • Paladins
  • Rangers
  • Rogues

Final Feat Grade for 5E War Caster

War Caster Feat Grade: A

Is the 5E War Caster Feat Worth It?

The War Caster feat is one of the best feats in 5E and is on the short list for every casting class. Many of the best spells in the game are concentration, so getting advantage on all Constitution saving throws to keep concentration is a huge buff. While it might not be quite as strong as resilient at high levels by pure mathematics, it’s better at low to mid-levels and offers additional benefits. Using a spell or cantrip as a reaction attack of opportunity is huge, and giving your sorcerer a magic shield to up AC is a really underrated strategy.

The combination of benefits make for one of the strongest casting feats in the game. There’s a reason it’s the most commonly taken feat by D&D players (and multiple surveys from major DnD sites shows it’s not even close) who play full casters.

War Caster Feat FAQ

Is War Caster or Resilient the better feat?

When focusing specifically on the trait of maintaining concentration, statisticians who are way more into the min/max optimization numbers than I am have figured out that War Caster is superior at low levels, hit about even around levels 8-10 and then the Resilient Feat is better for keeping concentration when hit.

Players would need to look at the other benefits of both feats to decide which one was the better fit for their build and their campaign.

When should I take war caster?

This is a feat that does major work from the beginning. While maxing out a casting stat early is important for most casters, adding the benefits of the war caster feat makes sense early or mid-game.

Do clerics need war caster in 5E?

This is a topic of a lot of debate and it’s arguable that with RAW clerics would need the war caster feat to cast spells while keeping their shield and weapon out. I have not met a single DM who enforces this rule up to this point. If in doubt, ask the DM, but it would be an unusual situation.

Even so, war caster is a very good feat for clerics in part because they are often part of the front line and therefore may see enemy creatures trying to move past them to get to the backline. Being able to throw an attack spell in their face could put a stop to that real fast.

Can you use a cantrip as a reaction in 5E?

Yes. While there are places in 5E where there is a distinct separation between cantrips and spells, that is not the case with War Caster. Rules creator Jeremy Crawford confirmed that the War Caster feat applies to both cantrips and leveled spells, as long as they meet the requirements stated in the feat itself.

Can you cast spells with a shield in 5E?

The general answer is no, however DMs may choose to interpret this different based on class, having martial clerics like Clerics get away with it, while classes like sorcerers and wizards do not unless they take a feat like moderately armored to get proficiency in shields.

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