How is Matt Smith not the 12th Doctor (since David Tennant regenerated first into himself and then into Matt Smith)? Then wouldn't Peter Capaldi be the 13th Doctor? (Because that regeneration was a gift from the Time Lords thanks to Clara.)

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    And it's more complicated than that, due to the existence of the Valeyard.
    – Spencer
    Dec 29, 2018 at 17:21
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    And the War Doctor. :p
    – Longspeak
    Dec 30, 2018 at 3:20
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    What about the war doctor played by John hurt? If you count his regeneration he should be 9th doctor, which screws up all numbers. Dec 30, 2018 at 16:26

6 Answers 6


Here's the "regeneration" you're referring to:

The key here is that, while the Doctor did use up one of his regenerations, he didn't actually regenerate. He used just enough of the regeneration energy to heal himself, then channelled the rest into his severed hand from "The Christmas Invasion", preventing himself from fully changing.

You can think of it like the scene in "Let's Kill Hitler" where River Song transfers the last of her regeneration energy into the Doctor to revive him: on both occasions, the energy brought him back to life, but he didn't regenerate. So he's still the Tenth Doctor.

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    I’m fairly certain 12 discusses this with Pond at some point, mentioning his “vanity issues” at the time, and how this was his last form. I just wish I could remember the scene. Dec 31, 2018 at 14:23
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    @EricMcCormick I think that was Eleven, discussing it with Clara during the Siege of Trenzalore.
    – F1Krazy
    Dec 31, 2018 at 16:53
  • That sounds right, although I didn’t quickly find a clip on YouTube substantiating it. ¯\_(ツ)_/¯ Dec 31, 2018 at 17:00

It's complicated, more complicated than anyone knows exactly and this is why:

In the episode "The Brain of Morbeus" The Doctor faced a Timelord, a criminal mastermind who had survived execution called Morbeus. In a desperate attempt to thwart his plans, The Doctor goaded Morbeus into a mental duel.

They were both hooked to a machine which pitted all their mental resources from each of their many lives against the other's, their will and their knowledge and their determination to win, and to live.

The effort killed The Doctor, and reduced his enemy Morbeus to an insane gibbering wreck who threw himself off a cliff, so The Doctor - even in death won.

Whilst he was hooked up to the machine, The Doctor's and Morbeus's previous personas were displayed one by one as they were drawn into the contest - these images appeared among others:

enter image description here Attribution: Peter 2018

None of the (lower row of) above images are of Doctors that we can pinpoint and name easily, they all appeared before the image of William Hartnell, Peter Cushing (had you forgotten him too? Here.) Michael Jayston (as per comments), David Bradley (Here) et al..

The Party line is that Peter Capaldi is the twelfth, but there's more to it, much more to it, perhaps more than even The Doctor himself knows - Rasillon knows, I don't.

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    Canonically, I'd expect that they're meant to be future versions considering that they're in a different colour with a sort of portally effect.
    – wizzwizz4
    Dec 29, 2018 at 21:08
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    @wizzwizz4 Possibly, but their costumes appear to be from Earth's past - admittedly that's no guarantee of anything. Dec 30, 2018 at 4:28
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    @Duckisaduckisaduck such linear thinking.
    – JAB
    Dec 31, 2018 at 0:11
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    @JAB True, I need a Tardis, for educational purposes. Dec 31, 2018 at 0:15
  • We certainly know by out of universe reasons that none of them can or will be future doctors on the show so this certainly complicates any numbering system based on regenerations.
    – user64742
    Dec 31, 2018 at 10:50

Canonically, there only is, was, and will ever be one Doctor. The numbering is simply a referencing device for commentating on the show.

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    You've had my +1, the rest of the answers are just waffle, including mine. Jan 2, 2019 at 23:38

Personally, I also thought that by regenerating into the "same" body, that ought to count as two separate Doctors. However, regardless of in-universe status, the numbering of the Doctors is really based on the out-of-universe actors who played the character. On that basis, since the actor did not change, the numbering of the Doctor did not change either.

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    Given the fuss Ten made about changing into a new body at the end (you know, about dying and a new man walking away with his memories) and how easily this went over, I conclude he didn't really regenerate here.
    – Mr Lister
    Dec 30, 2018 at 8:21

The numbers generally refer to the number of times the Doctor has regenerated, distinct from the number of times the Doctor has consumed one of his available regenrations.

In short, new face, new actor, new number.

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    The first Doctor was not the doctor after the first regeneration, and the War Doctor is not in the numbering scheme and was a regeneration, so only 9th Doctor and the first regeneration of 10th Doctor have the same 'Doctor number' as the number of times the Doctor has regenerated. (bbc.co.uk/iplayer/episode/p01mj6k8/… 54:26 the 11th Doctor refers to "regeneration number 13") Dec 30, 2018 at 22:56

There's another question on here that asks what "counts" as a regeneration - I've opined that it's not the amount of energy used, but the number of times the energy (and the process) is tapped into. The events of the show suggest they consider the rule to be the number of times the process is started.

This was all addressed in Matt Smith's last episode The Time of the Doctor. The War Doctor (played by John Hurt) was a regeneration The Doctor didn't acknowledge, but it certainly counted as a regeneration. So too did Ten's "partial" regeneration after getting hit by the Dalek beam. He chose to offload the regeneration energy into his severed hand. He retained the same body/regeneration, but the process was started, the energy was expended, so it too counted towards his twelve regeneration limit.

Moffat cannily hinted that the fans "had forgotten something" when it came to the regeneration limit, namely that Tennant regeneration. Comments online made it clear that damn near nobody forgot, and we were all keen to see what he was going to do, since by the rules, The Doctor had hit his limit.

So to answer the original question, Smith's regeneration indeed the twelfth regeneration, but the "extra" Doctor is The War Doctor. So technically, Eccleston was Ten, and Tennant was Eleven. They never "counted" the War Doctor, so Smith often referred to himself as "eleven", but he still counted as a regeneration.

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