Does a Wild Shaped druid with the War Caster feat have advantage on concentration checks?

Question

While planning out the new Druid I'm rolling, I found many discussions on the internet saying that the War Caster feat is useful to take as it helps the druid maintain concentration while using Wild Shape (including at least one occurrence on this site.)

The War Caster feat (PHB 170) says:

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.

(Other benefits omitted.)

However, the Feats section (PHB 165) says:

You must meet any prerequisite specified in a feat to take that feat. If you ever lose a feat's prerequisite, you can't use that feat until you regain the prerequisite. For example, the Grappler feat requires you to have a Strength of 13 or higher. If your Strength is reduced to below 13 somehow -- perhaps by a withering curse -- you can't benefit from the Grappler feat until your Strength is restored.

When you use Wild Shape, a couple of the many rules (PHB 67) say:

You can't cast spells, and your ability to speak or take any action that requires hands is limited to the capabilities of your beast form. Transforming doesn't break your concentration on a spell you've already cast, however, or prevent you from taking actions that are part of a spell, such as call lightning, that you've already cast.

You retain the benefit of any other features from your class, race, or other source and can use them if the new form is physically capable of doing so. ...

(Other rules omitted.)

So, it appears the logic goes like this:

1. Cast any spell that requires concentration
2. Use Wild Shape and continue concentrating on the spell
3. Druid no longer has the ability to cast spells (unless they are level 18+), but retains the benefit of all feats that the new form is capable of using (as a feat is a feature of the class or race - ASI or human variant)
4. War Caster feat can no longer be used as the prerequisite is no longer met since the Druid doesn't have the ability to cast at least one spell anymore
5. Any Constitution saving throws made to maintain concentration on a spell while taking damage will NOT be at advantage (assuming no other source of advantage is present)

Is my logic correct for a druid from 2nd to 17th level? Or is there some other rule or ruling that keeps the advantage for the Wild Shaped War Caster Druid when making these Constitution saving throws?

(Druids get Wild Shape at 2nd level; at 18th level, druids get the Beast Spells feature, which lets them cast spells that don't have material components while in Wild Shape. Thus, the question's only relevant at levels 2-17.)

Given the internet's love of pointing out when people are wrong, and me finding at least 3 instances where someone explicitly mentions War Caster as being useful while using Wild Shape, I'm inclined to think I've missed something. However, I can't find what I've overlooked in the rules. (Although, based on past experience, about 7 second after posting I'm sure I'll figure it out.)

Answer 1

Being prevented from casting spells isn't the same as losing the ability

To start with having the "ability to cast one spell" from a feature and not a magic item is the same as "being a spellcaster" as defined in the DMG (p. 135; clarified in Errata), so we can use those terms interchangeably.

The core of your question is whether having an effect saying "you can't cast spell" means you lose the ability to cast spells and therefore you no longer meet the prerequisites of War Caster. This isn't covered very well by the rules (shockingly), but we can look at some similar cases.

• Lets say all the spells of a spellcaster have a verbal component (as is very likely). They are standing in the effect of a silence spell. They now have no spells they can cast, but they categorically still have the Spellcasting feature it's just not doing too much for them.

• In a less likely scenario, say all the spells of a spellcaster have a casting time of one reaction. When the criteria for these reactions aren't met, they have no spells they can cast and so can't cast spells. However they still have an ability to cast spells.

• A very similar argument goes for a Paladin or Ranger (no Cantrips) who uses their last spell slot. They would not be able to cast any more spells, but they still have an feature which grants them the ability to cast spells.

Having the spellcaster count as "losing the ability to cast spells" would make them no longer be a spellcaster, and therefore no longer be attuned to any magical items which "requires attunement by a spellcaster". Losing attunement to your cool magical staff (or similar) because some cast silence on you or you used your last spell slot, is unfun, weird, and to a lot of players, dumb.

If a ruling making the game less fun isn't enough, also note that you would have to do a lot of on/off tracking on whether a creature counts as a spellcaster at any point of time, both for that feat (and others) as well as magical items. This adds complexity to the arguably most complex part of the game.

So does a Druid lose the "ability to cast spells and thus the benefits of War Caster? This would then hinge on them keeping their Spellcasting feature, which they should. Otherwise, 18th-level feature Beast Spells wouldn't do much, or would need to let them keep the feature without saying so in its text. And as a general principle features (and spells) only do what their description says.

We are now allowing the Wild Shaped Druid to have a Spellcasting feature without having the ability to use that feature (i.e. cast spells). This is consistent with the part of Wild Shape which determines retention of features:

You retain the benefit of any features from your class, race, or other source and can use them if the new form is physically capable of doing so. [...]

--- Player's Handbook p. 67

If we read it as two separate sentences:

You retain the benefit of any features from your class, race, or other source. You can use them if the new form is physically capable of doing do.

which isn't unreasonable.

Answer 2

Before I start let me make a few points

Spellcasting features states

Spellcasting Drawing on the divine essence o f nature itself, you can cast spells to shape that essence to your will. See chapter 10 for the general rules of spellcasting and chapter 11 for the druid spell list.

Multi-classing says this about spellcasting

Spellcasting Your capacity for spellcasting depends partly on your combined levels in all your spellcasting classes and partly on your individual levels in those classes. Once you have the Spellcasting feature from more than one class, use the rules below. If you multiclass but have the Spellcasting feature from only one class, you follow the rules as described in that class.

From this it is very clear that the spell casting feature itself is what grants the ability to cast spells. Additionally, it is this feature that determines the spell slots you have at your disposal. This is evident by the fact that spell slots is a subcategory of the spellcasting feature.

I would also like to take a moment to point out that there are many reasons why a character can't cast a spell. A few of these would be, having no spells in which you have the ability to provide components for, Having no cantrips or spell slots, Used up all available uses of your spells, being in wild shape form for the druid, being in rage, and many others.

If you can’t provide one or more of a spell’s components, you are unable to cast the spell.

spellcasting Ability Wisdom is your spellcasting ability for your druid spells, since your magic draws upon your devotion and attunement to nature. You use your Wisdom whenever a spell refers to your spellcasting ability.

Now to get onto the issue people have and to point out whats wrong with the train of thought.

From the wild shape description

You can’t cast spells, and your ability to speak or take any action that requires hands is limited to the capabilities o f your beast form. Transforming doesn’t break your concentration on a spell you’ve already cast, however, or prevent you from taking actions that are part of a spell, such as call lightning, that you’ve already cast.

The main argument here is the wording that you can't cast spells. Though you do retain the ability to take actions that are part of an ongoing spell and you can maintain concentration on the spell.

Also this

• You retain the benefit of any features from your class, race, or other source and can use them if the new form is physically capable of doing so.

I pointed this out because you clearly retain your spell casting feature, which is the ability to cast spells, however you can't use it because wild-shape states your form is unable to cast spells. This is the same as if you had donned armor you where not proficient in, you retain the feature that lets you cast spells, thus you have the ability to, however you are prevented from doing so.

So we know you have your spell slots, ability to use spells you have cast, ability to concentrate on spells, and the spellcasting feature.

Now what about the feat

War Caster Prerequisite: The ability to cast at least one spell

So the feat requires you to have the ability, it does not say you must be able to, but specifically mentions the ability. There is an argument that the wording ability and the word can't are connected.

Lets look deeper and see where all the wording ability to cast spells is referenced

the ability to use minor spells.

PG 11 PHB

you gain the ability to cast the beast sense and speak with animals spells,

PG 50 PHB

but the ability to cast cleric spells relies on devotion and

PG 56 PHB

infuses you with the ability to cast certain spells.

PG 68 PHB

you augment your martial prowess with the ability to cast spells.

PG 75 PHB

you gain the ability to cast spells.

PG 98

what we see is that most often the words "ability to cast spells" is used almost exclusively in the spellcasting, innate spellcasting features or when a class, race or other features grants the ability to cast a specific spell.

While other references instead say Can cast, or can't cast or some other way of talking about it.

Since the feat says "ability to cast spells" and this is granted by the spellcasting feature, it is not directly connected to being able to cast spells which can be stopped by something as simple as running out of spell slots, not having the correct components, using up your daily uses, or any number of conditions.

---

Since the following is true

You retain the benefit o f any features from your class,

PG 67 PHP under wild shape

Druids gain the Spell casting feature

Spellcasting feature grants "ability to cast spells" (which is evident in multiple entries for the feature)

you augment your martial prowess with the ability to cast spells.

PG 75 PHB

you gain the ability to cast spells.

PG 98

Additionally, the feat says you must have the ability to, not be able to

Ability defined as "possession of the means or skill to do something" Able defined as "having the power, skill, means, or opportunity to do something"

We can clearly see the definition of ability to does not require one to be able to, only that one knows how to.

thus one can have the ability to without being able to. But one can't be able to without having the ability to.

So if a person can't cast, they are not able, but they still have the ability to.

From a careful breakdown of the Core rulebooks, it is very easy to see that both as written and as intended Druids in wild shape maintain the ability to (they posses the skill to do so), because they maintain the feature that grants that skill. even if the Wild shape prevents them from being able to.

The entire argument for them to lose the use of the feat hinged on the words can't meaning loss of ability, though in truth can't means not being able to which has an entirely different meaning.