The Cleric’s legs strained as the giant’s hammer crashed down on her shield, gritting her teeth she returned the favor with a swing of the silvered mace in her other hand. The blow landed, with a slew of curses in Giant following the impact, and to her surprise, the giant began to turn. The confusion quickly settled as he soon heard what he had seen, her party members running from behind her to join the fray. The massive creature probably thought he was doing the smart thing by retreating, but as he began to move away she called upon her god’s power, channeling it into a burst of radiant energy from her mace. The giant didn’t get far.
Some mages spend their time secluded in a library, researching obscure lore to solve the mysteries of the universe, some create horrifying bear/owl hybrids, but some prefer to stride into the heart of combat with a shield in one hand, a weapon in the other, and a spell on their mind. For that last group, their preferred lifestyle poses some mechanical problems, this is where War Caster comes in.
You have advantage on Constitution saving throws that you make to maintain your concentration on a spell when you take damage. This is a huge boon to fullcasters, most of whom don’t have very good Con modifiers, making using concentration spells like Spirit Guardians in the middle of combat far more reliable.
You can perform the somatic components of spells even when you have weapons or a shield in one or both hands. The component rules are one of the more subtle aspects of the 5E rules, but effectively shut down a lot of spells for those wanting to have both hands occupied, even if one of them is holding a focus. This feat enables you to freely wield a shield and weapon/focus, or even two weapons, without worrying too much about how it will hinder your casting.
When a hostile creature’s movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature. Opportunity attacks are a part of combat that a lot of fullcasters can’t adequately compete in unless they choose to hold a weapon, which is usually far less effective for them than casting a spell. This aspect of the feat allows a fullcaster to really unload on an enemy that is trying to flee them or pass by them to another party member. This makes the difference between a meager dagger swipe for 1d4+2 and a casting of Disintegrate, for example.
This feat looks really handy to spellcasters, so surely if you can cast spells you’ll want War Caster, right? It’s not actually that simple, with different casting classes getting different amounts of value from this feat, so let’s take a look at who this feat is best and worst for. Note: We’ll be omitting any classes that can’t cast spells from their main class abilities in the ‘Least Useful For’ section, as you need to be able to cast at least one spell to qualify for the feat.
War Caster is most useful for
Wizards – This class benefits significantly from advantage on concentration saves and being able to make opportunity attacks with spells. Most Wizards won’t get any benefit from being able to cast with both hands full, but some builds will still appreciate that aspect, two weapon fighting Bladesingers, for example.
Clerics and Druids – These are listed together as their reasons for taking War Caster are identical: both have spell lists that heavily feature concentration spells and both have proficiency with shields with an incentive to hold a weapon in their other hand.
Warlocks – The advantage on saves for concentration is the primary benefit for this class, as the lower number of spell slots from Pact Magic increases the value of each slot. You really don’t want to lose concentration when you don’t have the spell slots to cast the spell again!
War Caster is least useful for
Artificers – These tinker-happy casters are unique in how they function, with every Artificer spell they cast getting a Material component added to it. This, combined with being able to use an infused item as a focus, means that the second bullet point of the feat is entirely useless to them. Meanwhile, the advantage to maintain concentration has lower value, as they have proficiency in Constitution saving throws, and access to abilities like Flash of Genius and the Mind Sharpener infusion, which makes it very unlikely that they would lose concentration, to begin with. The only bullet point that might be interesting to an Artificer is being able to use a spell for an opportunity attack, but that is also dependent on what subclass that Artificer chose.
Paladins – Between being a martial and their Aura of Protection feature Paladins are very likely to have a good Con saving throw modifier. Paladins are also able to use a shield with a holy symbol engraved/inlaid on it as a spellcasting focus, which reduces the value, somewhat, of the second bullet point, whilst the Paladin’s spell list isn’t compatible with the third bullet point.
We hope that this article has been informative and you were able to keep your concentration during it. If you’re interested in some spells to concentrate on then check out our spells section, or check out more feats in our feats spotlight.