Does a creature that is immune to all outcomes (conditions, damage, etc.) of an effect still make a saving throw?

Question

Let's say a 5th level Lore Bard casts fear on a violet fungus not knowing that it is immune to the frightened condition.

Does the violet fungus still make a saving throw? In particular, is a saving throw rolled which the Bard can use (and admittedly waste) its Cutting Words on? (A divination Wizard's Portent feature could also be used on, and be wasted by, such a saving throw.)

(I am interested in whether a saving throw game-mechanically happens and can be [fruitlessly] interacted with, not whether I explicitly need to pick up a die. It is clear to me the actual roll can be skipped in the interests of speeding up game-play.)

Answer 1

Yes

First we need to understand mechanically how immunity to a condition actually functions when a saving throw is involved. This can be observed by the following situation:

A Wizard casts Sunburst on an Ochre Jelly;

On a failed save, a creature takes 12d6 radiant damage and is blinded for 1 minute.

An Ochre Jelly is immune to the Blinded condition, but a saving throw is still called for.

Undead and oozes have disadvantage on this saving throw.

The Ochre Jelly is even making the saving throw with disadvantage, but is still unable to be affected by the blinding effect of the spell due to its immunity, which indicates that a condition imposed by a spell as the result of a saving throw has no effect.

If a Paladin casts Thunderous Smite (PHB, p. 282) on the same Ochre Jelly;

Additionally, if the target is a creature, it must succeed on a Strength saving throw or be pushed 10 feet away from you and knocked prone.

This is another example of the one part of the effect of the spell simply being ignored while a saving throw is required to be rolled because the Ochre Jelly is immune to the condition that the spell inflicts.

This is all to say that immunity to a condition would just mean that if this condition were to affect it, it would do nothing instead.

The Fear spell reads as such:

Each creature in a 30-foot cone must succeed on a Wisdom saving throw or drop whatever it is holding and become frightened for the duration.

The target still makes a saving throw as called for, but regardless of whether it fails or passes, it cannot be frightened. Any changes made by a portent or Cutting Words would be wasted if the characters were unaware of the immunity. However, RAW, this does also mean that a creature with immunity to the fear condition would still drop whatever it is holding as that is specifically not a part of the frightened condition, but an effect of the spell itself.

Saving Throws in the PHB pg. 179 reads as such:

A saving throw—also called a save—represents an attempt to resist a spell, a trap, a poison, a disease, or a similar threat. You don’t normally decide to make a saving throw; you are forced to make one because your character or monster is at risk of harm.

And further in the PHB on pg. 205

Many spells specify that a target can make a saving throw to avoid some or all of a spell’s effects. The spell specifies the ability that the target uses for the save and what happens on a success or failure.

Other than the slightly loose wording on page 179, nowhere does it indicate that a saving throw is ever optional or is not to be rolled regardless of the outcome of the effect, and a creature is unable to even willingly fail a saving throw as per Jeremy Crawford's response to this question.

Only the possible reading of "can" from page 205 would indicate a possibility of having an option of a saving throw, but this can be negated by the specific wordings of spells, such as the following:

A better example to consider for this question that has no extra clauses in the effect would be Blindness/Deafness

You can blind or deafen a foe. Choose one creature that you can see within range to make a Constitution saving throw. If it fails, the target is either blinded or deafened (your choice) for the duration.

RAW, "to make a Constitution saving throw" indicates that regardless of the Ochre Jelly's immunities, the save is rolled. It does not state "unless the target is immune" or "if the condition imposed by this spell would have no effect on a success". On a fail, the condition simply does not take effect because of the immunities of the target. Additionally, this would also indicate that the spell is continuing for the duration or until a successful save is rolled.

At the end of each of its turns, the target can make a Constitution saving throw. On a success, the spell ends.

Obviously as has been stated before, a GM may decide to rule it however they wish in the interest of time or enjoyment as they are the final word at their particular table, and I am sure that many would agree it would make the most sense to not make needless rolls or have your players waste resources; but as everything is written and strictly speaking a roll would need to be made regardless of immunity to the effect of a spell that calls for a saving throw because it never says otherwise.

Answer 2

No

The violet fungus would not make a saving throw.

In the PHB, under the "Saving Throws" heading (p. 179), it says:

A saving throw — also called a save — represents an attempt to resist a spell, a trap, a poison, a disease, or a similar threat.

The violet fungus cited as an example would not make a saving throw. It is not resisting the fear spell, it is just incapable of being affected by its results.

The PHB goes on:

You don’t normally decide to make a saving throw; you are forced to make one because your character or monster is at risk of harm.

It is not "at risk of harm" from the fear spell, so it is not forced to make a save.

The spell says:

Each creature in a 30-foot cone must succeed on a Wisdom saving throw or drop whatever it is holding and become frightened for the duration.

In this case, the general case is that each creature in the cone must succeed on a save or drop whatever it's holding and become frightened; in the more specific case of creatures immune to fear, they do not have to succeed the saving throw, therefore there's no reason for those creatures to make the saving throw.

Similarly, a creature without vision would not save against being blinded, a creature incapable of being hurt by fire would not save against fire damage.

The DMG, under the "Saving Throws" heading (p. 238), says:

A saving throw is an instant response to a harmful effect and is almost never done by choice.

In the case of the violet fungus, it can't be frightened, and so the fear spell is not a harmful effect for it.

The DMG goes on to say:

A save makes the most sense when something bad happens to a character and the character has a chance to avoid that effect.

Nothing bad is happening to the violet fungus.

Or... Maybe?

Seidr's answer makes a reasoned case that yes, the violet fungus makes a save. That's one way to look at it. It's possible that even strictly within the rules, different tables may approach the question differently.

Answer 3

Creatures with immunities to conditions must still make saving throws against effects, even if the sole outcome of the effect is to attempt to confer a condition that the creature is immune to

The reason I argue this position is an unusual interaction I found for Tiamat, in the Rise of Tiamat adventure module (page 92):

Condition Immunities blinded, charmed, deafened, frightened, poisoned, stunned
[...]
Multiple Heads. Tiamat can take one reaction per turn, rather than only one per round. She also has advantage on saving throws against being knocked unconscious. If she fails a saving throw against an effect that would stun a creature, one of her unspent legendary actions is spent.

If we were to argue that creatures which are immune to a specific condition do not make saving throws against effects which confer that condition, then the feature described here would make no sense. Their statblock first confers immunity to the Stunned Condition, but then a later feature dictates an outcome if Tiamat is affected by an effect which confers the Stunned condition. In order for this feature to make logical sense, it needs to follow that Saving Throws are always rolled, even if the target is otherwise stated to be immune to its sole effects.

So Saving Throws are always rolled, regardless of the immunities the targeted creature has.

Answer 4

The rules don't cover these cases well.

If it matters, I would say it depends if the creature tries to avoid the attack or completely ignores it. E.g. Imagine a PC makes a "Dex save vs. fire damage" attack.

• If the attack is one the creature would be mostly unaware of, it doesn't make a save. E.g. something ethereal might ignore damaging attacks on the material plane.
• If the creature knows its immune and deliberately ignores the attack, it doesn't make a save. E.g. A boss monster with fire immunity walking intimidatingly straight through a stream of fire.
• If the creature tries to dodge because it doesn't know what that bolt of magical energy is going to do until too late, it does make a save, and that determines the difference between whether it dodges, or is hit but unaffected by what happens.
• If the creature tries to dodge because it has immunity of a form where fire might be inconvenient or uncomfortable, even if not deadly, then it does make a save, and that determines whether it escapes due to dodging or due to its immunity, which might matter if it's carrying anything flammable, sometimes.

I would say that, in those cases where the creature naturally would make a save, there's a potential for a PC to try to use an ability that affects saves. Even if the creature doesn't try, if they're eager to try to affect its save, I'd say that they could. After all, that ability happens as the attack hits, you may see the dice rolled, but you can't see the in-world results beforehand.

However, I wouldn't bring this up too much, because it's a lot of effort tracking things that usually don't matter and will make the PCs feel bad. I would only think about it if the PCs are notably meeting an enemy with unknown abilities for the first time, and it makes for a good story when they don't know what might work and what doesn't.

Answer 5

The answers of Seidr and Jack already look at two sides of RAW. I offer a different approach, as you didn't ask strictly about RAW.

If we consider RAF (rules as fun) as defined by the Sage Advice Compendium:

Regardless of what's on the page or what the designers intended, D&D is meant to be fun, and the DM is the ringmaster at each game table. The best DMs shape the game on the fly to bring the most delight to their players. Such DMs aim for RAF, "rules as fun".

I would strongly consider ruling in the favor of the players here, that they do not waste an ability on a roll that doesn't have any effect. It feels quite bad to use an ability when it can't have any effect, and the players may become cautious doing so until they know the immunities of an enemy. Immunities by themselves are already annoying enough and have this effect; it shouldn't be amplified. In particular, new players that already maybe sometimes forget what tools they have for a situation could now have extra doubt whether to use them.