How do multiple castings of True Polymorph interact?

Question

When targeting a creature changed by any form of polymorph affect (Polymorph, Shapechange, Wild Shape, or True Polymorph), do you target the original creature, or the creature in its current form?

Some examples are called for to make this understandable.

A fighter has True Polymorph cast on him, changing him into a dragon. When a second wizard targets the fighter/dragon entity with another True Polymorph, turning him into an owlbear, what is the second wizard's actual target? The dragon, which is the current form, or the fighter, which was the original form?

The behavior I'm most interested in is the result of one spell failing. In the above case, if the first wizard loses concentration, that True Polymorph ends. Per the spell description, the fighter should return to being a fighter. However, the second spell is still active, making him an owlbear.

• If the second spell targeted the fighter, this spell should remain, and the fighter will remain in owlbear form despite the first wizard losing concentration.
• However, if the target of the second casting was the dragon, it should fail, as the target (the dragon) no longer exists.
• This interaction goes both ways: if the second wizard loses concentration, if he targeted the fighter, then the owlbear becomes a fighter. If he targeted the dragon, then the owlbear becomes a dragon.
• What causes the spells to fail actually doesn't matter. I've presented it as concentration loss for simplicity.

Answering the above situation will handle most cases of this problem, but we have to consider some additional cases with True Polymorph permanency.

• If the second casting targets the fighter, not the dragon, would this instead target the dragon if the original True Polymorph spell was made permanent before the second casting took place?
• If the second casting targets the fighter, not the dragon, and after the second True Polymorph is cast the first True Polymorph becomes permanent, does this end the effect of the second casting (since its target no longer exists, as the fighter is now permanently a dragon)?

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EDIT: The original form of this question used damage as the means by which the spells ended in my examples, causing confusion with permanency which was not intended. My sincerest apologies for such a drastic change after answer(s) were submitted. The revised question should address all cases of damage as a means of ending a polymorph-style spell, except the case of True Polymorph's permanent effect; that requires and answer to the linked question and is outside this question's scope.

Answer 1

Short answer is that the spell targets the creature in its current form.

Who Is Really In There?

Regardless of the form the creature is in after the first True Polymorph, or was originally in, the creature gets a saving throw if it is unwilling to change under a given instance of this spell.

True Polymorph Targets a single Creature

True Polymorph creature-to-creature version results in a creature with a new form: another creature. Any subsequent casting is an attempt to overwrite a previous casting, but that does not change the fact that the second instance is being cast upon a creature (the new form): a creature affected by the spell gets changed into (some new form) under two conditions:

• Willingly
• On a failed Wisdom save.

  Choose one creature or non-magical object that you can see within range. You transform the creature into a different creature, (SRD Spell Description, p. 185).

The second wizard has only one creature to changed into that owlbear, not two. If the first caster loses concentration, the dragon becomes a fighter. That is because the two don't happen at once, as you described in your example.

This is a turn based game, so something has to happen first. If the second wizard cast the spell while the first has concentration on the Polymorph, that gets adjudicated first. If the first wizard loses concentration before the second wizard casts the spell, that gets revolved (dragon becomes fighter) first.

This means that if the first wizard is still concentrating, the only creature the second wizard has to work with is the dragon.

If the second wizard casts the spell on the dragon while the other wizard is concentrating, and not after it is permanent, then resolve the conflict with the following in mind:

An unwilling creature can make a Wisdom saving throw, and if it succeeds, it isn’t affected by this spell.

1) Have the dragon make a saving throw. It is the creature being targeted. If he willingly accepts True Polymorph from the first wizard, this save should probably be rolled first: he's the creature the other wizard is trying to change into an owlbear. If he is willing to be changed, no saving throw is needed. We then address the problem of two instances of the spell trying to affect the same creature at the same time.

The target’s game statistics, including mental ability scores, are replaced by the statistics of the new form. It retains its alignment and personality.

If the dragon fails the save -- true polymorph uses the new form's stats so our changed Fighter must use the Wisdom Save for the dragon ---- then it gets turned into an owlbear ... pending the outcome of the contest between two wizards.

If the Fighter/Dragon makes the save, then no change happens.

(You could do this contest first, and if the second wizard wins, then roll the save).

Credit to @Dale M for raising this point: when two of the same spell are applied to the same target, only one affects it. (PHB p. 205)
* In the case of True Polymorph versus Polymorph, 9th level spell beats 4th level spell
* In the case of Shapechange versus True Polymorph, it is 9th level versus 9th level spell, but since the Shapechange is cast on "self" you are dealing with the save versus True Polymorph in the Shapechanged form

How do you decide between the first and second instance of the True Polymorph spell?

The first could be overcome by the second wizard's casting based on a different game rule, since there can be only one instance of that spell affecting that creature. Two characters are trying to do the same thing at once? Use rules for a Contest.

2) Who wins the Contest?(p. 58 of the Basic Rules).

Contests

Sometimes one character’s or monster’s efforts are directly opposed to another’s. This can occur when both of them are trying to do the same thing and only one can succeed ... In situations like these, the outcome is determined by a special form of ability check, called a contest. Both participants in a contest make ability checks appropriate to their efforts. They apply all appropriate bonuses and penalties, but instead of comparing the total to a DC, they compare the totals of their two checks. The participant with the higher check total wins the contest. That character or monster either succeeds at the action or prevents the other one from succeeding.

I'd recommend using the Intelligence (spell casting stat) as the basis for the contest. That means that the situation you set up about dueling concentration doesn't have a chance to happen -- it's a turn based game.

Result of the contest is either:

• The first keeps his concentration up, and he wins
• The second overcomes him as a result of the Contest being resolved and the dragon is changed into an owlbear.
  • (Apply saving throw, or not, based on the target being willing, or not).

Do the rules specifically state that for this spell? No. What the Contest rule provides is a simple way to resolve it, keeping in mind that things happen in a sequence in a turn based game, and that only one instance of this spell can apply to a given creature at a time.

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Further comments

Note the position the second wizard is in, in terms of sequence of events.

True Polymorph / Casting Time: 1 action (SRD. p. 185)

Either the second wizard succeeds in his attempt to change the dragon into something else, or he fails. You can do it by save, by contest, or both if the dragon/fighter is not willing to change into a new form.

If the fighter was not willingly changed into a dragon, he might accept the second wizard's spell and not fight it. Only an unwilling creature rolls a save versus this spell.

An unwilling creature can make a Wisdom saving throw, and if it succeeds, it isn’t affected by this spell.

How does the spell work? First, it changes a creature's shape. Then, the wizard concentrate on the creature staying in the new shape, either short term or long term. The second wizard cannot concentrate on maintaining the new shape of a creature that he did not yet change into an owlbear.

This step by step approach avoids having to rule about "who is really in there?". Even though the polymorphed creature retains its personality and alignment (who it is), you can make a ruling on whether the warrior rolls a save versus the second spell, or not. Just ask the player.

Each casting of the spell allows a save for an unwilling creature who is the target.

This interaction goes both ways: if the second wizard loses concentration, if he targeted the fighter, then the owlbear becomes a fighter. If he targeted the dragon, then the owlbear becomes a dragon.

The owlbear only changes into a dragon if the dragon was permanent. Otherwise, he becomes the Fighter, since the contest had to be decided in the second wizard's favor in order to turn the dragon into the owlbear in the first place.

Answer 2

From the Player's Handbook (p. 205) and the Player's Basic Rules (p. 81):

The effects of different spells add together while the durations of those spells overlap. The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect--such as the highest bonus--from those castings applies while their durations overlap.

For the specific case you mention of two True Polymorph this rule would apply. You need to decide what "... most potent effect ..." means. Some ideas:

• Highest spell slot wins (irrelevant for True Polymorph - 9th level but could work for other spells)
• Highest spell casting bonus wins
• A contest (PHB 174)
• Most/least recently cast

Interactions between different spells are sufficiently complex that each is probably worthy of its own question.

Answer 3

One casting suppresses the other

There are three main points you need to undeerstand to understand how two castings of true polymorph interract with one another.

• The target of true polymorph is the "one creature or nonmagical object" you choose. It is the same target regardless of how it transforms (by this or other means), but if it transforms into something that is neither one creature, nor one nonmagical object, then it is no longer a valid target.
• The effect of true polymorph is a transformation that you choose within limits (i.e. the CR) imposed by the target as it is when you cast the spell.

• If someone else casts true polymorph on the same target to transform it into an owlbear, then the rules for Combining Magical Effects apply:

  The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect—such as the highest bonus—from those castings applies while their durations overlap, or the most recent effect applies if the castings are equally potent and their durations overlap.

  Note that the less potent spell does not end, so it still exists even while its effects do not apply. In situations where the spell exists but has no effect it is generally said to be suppressed.

Which casting is more potent?

This is not well defined, so it is ultimately up to the DM. The most obvious measure is the spell level, but that is always 9th level in our case. At this point, the DM can decide that the castings have equal potency so the most recent one suppresses the other. Alternatively, the DM could look at other measures, such as: a skill contest between the casters involved; the CR of the transformations; the remaining duration; etc.

But for the purpose of this answer, let's explore all the outcomes.

The first casting is more potent

In this case the transformation into a dragon continues as normal, whereas the transformation into an owlbear does not happen.

If the second casting ends before the first casting, then the transformation into a dragon continues as normal. When the first casting ends too, the transformation into a dragon ends.

If the first casting ends before the second casting, then the transformation into a dragon ends and the transformation into a owlbear happens. When the second casting ends too, the transformation into an owlbear ends.

The second casting is at least as potent

In this case the tranformation into a dragon ends and the transformation into an owlbear happens.

If the first casting end before the second, then the transformation into an owlbear continues. When the second casting ends too, the transformation into an owlbear ends.

If the second casting ends before the first casting, then the transformation into an owlbear ends and the transformation into a dragon resumes. When the second casting ends too, the transformation into an owlbear ends.