Do Smite spells work on Tiamat?

Question

Tiamat has the Limited Magic Immunity trait, I know that much. But the wording confuses me:

Unless she wishes to be affected, Tiamat is immune to spells of 6th level or lower. [...]

I understand spells like fireball or suggestion because Tiamat would be the target for those spells (or with fireball, the area around her).

Since the smite spells (like brandishing smite, searing smite, etc.) have a range of Self, would she take the extra damage/be subject to the affects if a creature that cast one of those spells hit with the weapon attack?

On the same line of thought: If a creature with a regular AC of 20 casts shield of faith (bringing their AC up to 22), does Tiamat ignore the spell, and thus only need a total of 20 on her attack roll to hit?

Is Tiamat subject to the extra effects of smite spells when hit with an attack? And can she circumvent shield of faith?

Answer 1

'Affected' can be ambiguous but is somewhat defined in the rules.

From the rules on spellcasting, specifically the range of spells, from the Basic Rules / Player's Handbook there is a quite clear statement what creatures are affected by spells with a range of self (emphasis mine).

Most spells have ranges expressed in feet. Some spells can target only a creature (including you) that you touch. Other spells, such as the shield spell, affect only you. These spells have a range of self.

Although I don't think there is a clear definition for every type of range and the creatures those spells 'affect' or 'target', the quoted rule quite deliberately states what creatures are affected by spells with a range of self.

Going by this the various spell smites, with their range of self, by RAW only affect the caster and not Tiamat. They could thus work.

Whether they actually do is in my opinion still a bit of an edge case, although these smite spells have a range of self they still quite directly affect (going by the normal definition of the word) the target of the weapon attack they are a part of. Although mentioned here and there, 'affected' is not a precisely defined game term and it can be more than reasonable for a DM to handle ranges of self on a case by case basis.

Answer 2

The key word is "affected"

If a spell would "affect" Tiamat, then this trait may apply. What this exactly means is unclear, as there is no proper definition for this word, or any clarification in the rules.

The english definition of the word itself is ambiguous, since it can apply both to direct or indirect influences.

As such, it is up to the DM to draw the line and decide what definition of "affected" they want to use.

Answer 3

How powerful do you want her to be?

Tiamat ought to be the ultimate boss fight. To my mind, it would be daft for her to be inconvenienced by a Wall of Force spell - even though she isn't the "target", I let her trample through unimpeded.

For player buffs, I rule that those that target a player can still work (Bless adds 1d4 to hit, Guardian of Nature adds 1d6 force damage etc), but those that target her don't work unless L7 and above.

The smite spells specify that damage and effects are applied "to the target". So for me, they're a "no". Similarly, I wouldn't let a player Banishing Smite a rakshasa.

Answer 4

The consensus I can find from similar questions about fighting a Rakshasa is that the base Divine Smite is not considered a spell, and should affect her. They don't outright mention other smites in any of the sources I checked.

For shielding spells, it is generally agreed that it can't ignore those, as it just raises the AC of a character. See this specific response to a similar question here.

Answer 5

The creature trait, Limited Magic Immunity, can be difficult to adjudicate.

But let's take a closer look.

If we look at the Rakshasa from the Basic Rules, it has this feature.

Limited Magic Immunity. The rakshasa can't be affected or detected by spells of 6th level or lower unless it wishes to be. It has advantage on saving throws against all other spells and magical effects.

There is an addition here, from the Monster Manual errata.

Rakshasa (p. 257). Limited magic immunity: the first sentence now reads, “The rakshasa can’t be affected or detected by spells of 6th level or lower unless it wishes to be.”

The original text was

The rakshasa is immune to spells of 6th level or lower unless it wishes to be affected.

Unofficial designer tweets

There are several tweets addressing questions about LMI, but they do not answer all questions, and sometimes create new ones.

• Q - Does a Rakshasa’s ‘Limited Magic Immunity’ protect it from weapons enhanced by Shillelagh?
• A - Shillelagh and magic weapon are spells. Limited Magic Immunity prevents a rakshasa from being affected by spells of 6th level or lower, unless it wishes to be. - JC
• Q - If I use divine Smite on a Rakshasa who has limited spell immunity, does he take any damage?
• A - don't believe it would be immune, since spell is affecting your weapon, not targeting rakshasa. - MM
• Q - Rakshasa can pass through Wall of Stone? It is immune of a Fire Elemental conjured by a 5th level Conjure Elemental?
• A - Because of the Limited Magic Immunity trait, a rakshasa could stroll through the wall created by the wall of stone spell, but not if the wall becomes permanent and nonmagical (aka undispellable). - JC
• A2 - A rakshasa's Limited Magic Immunity offers no protection against a summoned creature. The creature's presence is a spell effect. The creature itself is not a spell effect - JC

The Mike Mearls comment seems to imply a spell targeting you (or your weapon) would still work, but that doesn't agree with Jeremy Crawford's answer regarding Magic Weapon. If we ignore MM's comment, this starts to give us a few more guidelines, like an instantaneous effect that doesn't last, or an effect with a duration would not affect the LMI target.

Reddit

There’s a reddit post with this answer.

Magic users have a whole brace of options against [a creature with Limited Magic Immunity].

• 7th level or above spells (above the LMI threshold)
• Summon spells
• Buff spells on other characters
• Defensive spells like counterspell and shield
• Spells that create an instantaneous effect that then later affects the Rakshasa, like a stone-shaped sword.
• Spells with a radius including the Rakshasha that continue to function at least partly as normal through the LMI such as silence. (The Rakshasa could still cast a spell as the silence does not affect them but the area still prevents all sound from escaping so functionally, they are still silent)

I tend to agree with most of this interpretation, although Counterspell seems to be up for debate, and Shield probably wouldn't work, since although it's defensive, it is a spell effect that has a duration. So to answer your question,

Do Smite Spells work on Tiamat?

Although those spells have a range of self, they are not instantaneous, leaving a non-magical item, rather they are spell effects with a duration, so

No, but ask your DM.

But that doesn't mean all spells are useless.

Further, you didn't ask, but since Divine Smite, the class feature isn't technically a spell, the answer is more difficult. One could argue they are fueled by spell slots and are "magical" in nature, but the ability specifically calls out spells, so in this case, I would imagine a DM may rule a creature with LMI, or specifically Tiamat, is not immune.

Answer 6

There are several "smite" spells: Banishing, Blinding, Branding, Searing, Staggering, Thunderous, Wrathful. Each of them states "If the attack hits, deal X damage" where X is some dice of some damage. So this is what is damaging Tiamat, not the spell itself. So check if Tiamat is immune to that damage, the spell has nothing to do.

Damage Immunities acid, cold, fire, lightning, poison; bludgeoning, piercing, and slashing from nonmagical attacks

The paladin's divine smite states:

Divine smite "Starting at 2nd level, when you hit a creature with a melee weapon attack, you can expend one spell slot to deal radiant damage to the target, in addition to the weapon’s damage. The extra damage is 2d8 for a 1st-level spell slot, plus 1d8 for each spell level higher than 1st, to a maximum of 5d8. The damage increases by 1d8 if the target is an undead or a fiend, to a maximum of 6d8."

Again, the damage is extra damage of radiant damage. Is Tiamat immune to radiant damage?

With "Shield of Faith", the target gains a bonus +2 AC. The target gains a bonus, Tiamat does not gain a malus. Is Tiamat emitting an antimagic field suppressing all the spells? No - limited immunity is not antimagic.

Limited Magic Immunity Unless she wishes to be affected, Tiamat is immune to spells of 6th level or lower. She has advantage on saving throws against all other spells and magical effects.

In my opinion, rules are pretty clear and smite spells, smite ability and shield of faith work.