The spell clearly says that it does not affect a shapechanger.

Shapechangers are not affected by this spell.

But has nothing about the opposite.

Would that mean that I can change a Goblin into a Doppelganger and that Doppelganger cannot then ever be transformed again with a True Polymorph spell?


2 Answers 2


The spell description doesn't say you can't

Preface: You cannot true polymorph a Goblin into a Doppelganger.

From the spell description. (Goblin is a CR 1/4 creature).

If you turn a creature into another kind of creature, the new form can be any kind you choose whose challenge rating is equal to or less than the target's (or its level, if the target doesn't have a challenge rating).


If you chose a CR 3 creature like a Killer Whale, the spell's language indicates that it is the new creature: a Doppelganger. (Likely one with a taste for raw herring). Why? Nothing in the spell description says that you can't.

  • Rulings versus Rules: A DM might rule that due to the nature of the Doppelganger that the prohibition works both ways. I'd find that a reasonable ruling, but the specifics of the spell don't prohibit the change into a Doppelganger.

The Fine Print

There's some fine print to consider (at least in the SRD version of True Polymorph, p. 188).

If you concentrate on this spell for the full duration, the transformation lasts until it is dispelled.

The "full duration" refers to the hour of concentration it takes to make the true polymorph permanent. That true polymorph is "until dispelled" is shown in the SRD and in editions of the PHB after the first one was issued.

The Doppelganger can use its action to polymorph into a Small or Medium humanoid it has seen, or back into its true form.

Its true form is now a Doppelganger, not a Killer Whale. It can't change back into its old form to go hang out with its orca friends (It could have done that had it originally been a CR 3 humanoid, for example a Hobgoblin Captain). Might the Doppelganger want to return to being a Killer Whale?

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 someone knows that the Doppelganger was originally a Killer Whale and wants to return it to that form, or if the now-Doppelganger encounters an effect that dispels magic, then this subsequent dispelling returns it to Killer Whale form by either a friendly or hostile action.

Is that really a prince inside that frog?

This raises the in-game question of "Why would he want to be a Killer Whale again?" (Beyond the obvious case of his agent wanting him to star in Free Willy 5: the money's too good!) That's up to the DM to decide based on the story and motivations of the NPC's and monsters under his control. Something about the smell of fresh herring, down by the docks at midnight, awakens a yearning deep in the Doppelgangers heart ...

In that case, convincing someone to cast another true polymorph would be wasted effort, and would not make the change per the rule you cited. A dispel magic spell could if the DC check is successful, and a dispel magic spell would if it is cast from a 9th level spell slot.

Dispel Magic(p. 136)

Choose one creature, object, or magical effect within range. Any spell of 3rd level or lower on the target ends. For each spell of 4th level or higher on the target, make an ability check using your spellcasting ability. The DC equals 10 + the spell’s level. On a successful check, the spell ends. At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you automatically end the effects of a spell on the target if the spell’s level is equal to or less than the level of the spell slot you used.

There's another way that the Doppelganger would revert (at least for a while) to its original Killer Whale form: it encounters an antimagic field.

Any active spell or other magical effect on a creature or an object in the sphere is suppressed while the creature or object is in it. (SRD p. 117)

Antimagic field lasts for up to an hour. Will the Killer Whale survive for an hour if the antimagic field is not encountered in the water? That depends on the situation, and might be the core plot hook for Free Willy 6!

  • \$\begingroup\$ Very well thought out and made me smile more than once... +1 for you. ;-) \$\endgroup\$
    – Matthew
    Commented Sep 4, 2016 at 8:04
  • \$\begingroup\$ I don't know where you found that clip but nowhere does it say the permanent version of tp can be dispelled \$\endgroup\$
    – Nemenia
    Commented Sep 4, 2016 at 20:33
  • 1
    \$\begingroup\$ As I pointed out in the text, it is in the SRD, p. 188. Take a look, it is for free at the Wizards web site. The discussion on that is found at the next two links provided. Others have found that to be the case in later printed versions of PHB, though not the first. (Mine, for example, does not have it)). Because it can be dispelled, how? The obvious case is via dispel magic. \$\endgroup\$ Commented Sep 4, 2016 at 22:17
  • \$\begingroup\$ Relevant Crawford tweet supporting Korvin's statement: twitter.com/JeremyECrawford/status/723569059640401921 \$\endgroup\$
    – V2Blast
    Commented Mar 23, 2018 at 22:20
  • \$\begingroup\$ Another tweet about the target of the spell no longer being valid twitter.com/JeremyECrawford/status/736269988885995521 \$\endgroup\$
    – GcL
    Commented Jun 6, 2018 at 13:10

RAW - You can make a shapechanger, but it will instantly change back

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

When you transform a creature using true polymorph they are, by definition affected by the spell for the entire time the spell is active.

A spell's duration is the length of time the spell persists. A duration can be expressed in rounds, minutes, hours, or even years. Some spells specify that their effects last until the spells are dispelled or destroyed.

True polymorph has a duration of 1 hour or until dispelled. For that entire time, true polymorph is affecting the target.

If I turn a creature into a troll, that troll is continuously under the effects of true polymorph thus keeping the troll from becoming the original creature again.

If you try to change something into a shapechanger, it will change, but then it will instantly change back because they are now a shapechanger and thus cannot continue to be affected by the spell per the spells description.

Since they are a shapechanger, they don't even get a save. They automatically fail and would revert to their previous form. The save is only for creatures that are unwilling, but a shapechanger (regardless of willingness) can never be affected by the spell.

Rules as fun - Yes

True polymorph is a 9th level spell and an incredibly powerful one. PCs can already use it to change their form to be so many other immensely powerful creatures that it seems silly to forbid this based on the strict ruling of the spell. As DM, I would likely allow it.

  • \$\begingroup\$ As was discussed in chat a while back: for the first hour, it is something else being held in the shape/form of a doppelganger, not a doppelganger. Once the hour is over, it is now a doppelganger (original rule) and thus it can't in the future be polymorphed. Or, the spell is permanent and it needs to be dispelled ... but it can't be polymorphed again since it is now a doppelganger. In other words, at the point where it becomes a doppelganger it is no longer being concentrated upon. \$\endgroup\$ Commented Mar 23, 2018 at 18:34
  • \$\begingroup\$ @KorvinStarmast: "The target’s game statistics, including mental ability scores, are replaced by the statistics of the new form." I'm not sure how that implies anything other than the polymorphed creature is a doppelganger for all intents and purposes (including having the Shapechanger subtype which is the only really relevant part anyways). \$\endgroup\$ Commented Mar 23, 2018 at 18:36
  • \$\begingroup\$ Because that is only true while the spell caster is concentration on the form. The failure of the spell save is what is driving the train, and the new form is held until concentration ends. (Granted, this whole thing is a bit of a paradox ...) \$\endgroup\$ Commented Mar 23, 2018 at 18:42
  • \$\begingroup\$ @KorvinStarmast Maybe I am just not understanding what you are saying here. Are you saying that the creature after failing the save and assuming all the statistics of a doppelganger is not considered a shapechanger at that exact moment? And that they are only considered that after an hour? \$\endgroup\$ Commented Mar 23, 2018 at 18:47
  • \$\begingroup\$ it is a temporary condition, a condition that is being made possible by the concentration on the 9th level spell. It is still an "x" being held in doppelganger form because of the concentration on the spell. That's the simple way to parse it. I understand what point you are getting at, in terms of "it's a whole new creation" which, as I read it, is only true once the one hour of concentration has been completed. The actual answer of "why do you want to turn something into a doppelganger" is more apropos, but there's doubtless a case in a game somewhere that it's the perfect idea. \$\endgroup\$ Commented Mar 23, 2018 at 18:53

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