The Night of the Doctor | Doctor Who - BBC
Why Science Fiction & Fantasy Stack Exchange recommends it
Science Fiction & Fantasy Stack Exchange answerers cite it as primary canon evidence for how regeneration works, the War Doctor's place in the numbering, and whether a Time Lord can choose gender.
Recommended by 0 people across 0 different months, 2013 to 2015.
What it is
The Night of the Doctor is a roughly seven-minute BBC mini-episode released in 2013 ahead of the Doctor Who 50th anniversary. Paul McGann returns as the Eighth Doctor, who dies on Karn and is revived by the Sisterhood of Karn, who let him choose his next regeneration, leading into the War Doctor.
Cited in 3 Wikipedia articles, including The Doctor, The Day of the Doctor, The Night of the Doctor.
What people said
Cites F'x · 2013-11 · Science Fiction & Fantasy Stack Exchange · on “Why doesn't the Doctor regenerate immediately in “The Night of the Doctor”?”
In today's The Night of the Doctor [this video] , we see the Eight Doctor's death… yet, instead of regenerating, he is “revived” by the Sisterhood of Karn. So why did the regeneration not kick in as soon as he was dead? Is there “precedent” in the canon for this dead-but-not-yet-regenerating state of the Doctor?
Cites Josh · 2013-11 · Science Fiction & Fantasy Stack Exchange · on “Should the Doctor's enumeration be changed?”
To add to my comment to @tombull89 , I totally forgot to mention the "Night of the Doctor" prequel minisode which further shows the War Doctor's place in the lineage: [this video]
Cites Keavon · 2014-08 · Science Fiction & Fantasy Stack Exchange · on “Can the Doctor be female?”
In "The Night of the Doctor" mini-episode, as the 8th Doctor is dying, he is offered to choose what characteristics he will regenerate into. … our elixir can trigger your regeneration, bring you back. Time Lord science is elevated here on Karn, the change doesn't have to be random. Fat or thin, young or old, man or woman? (click to watch) [this video] Since this states that the change is random, and since the Doctor has not become a woman (excluding Doctor-Donna) in all of his regenerations, it is unlikely that Time Lords can change gender by chance during a regeneration. However, this also confirms that a gender change remains possible, i.e. by harnessing the elevated Time Lord science on Karn.
Cites Elliott Frisch · 2014-11 · Science Fiction & Fantasy Stack Exchange · on “Was Missy lying about her true identity?”
The Doctor lies too. But I expect that she's the Master. For a second I though Romana and we'd get to see the wonderful Mrs Dawkins (nee Ward) [LINK] regenerate ala *The Night of the Doctor* [this video] but it was not to be.
Cites KutuluMike · 2015-02 · Science Fiction & Fantasy Stack Exchange · on “dr who The war doctor how does he fit into the whole story?”
I suspect you have misheard or misunderstood something that David Tennant's Doctor said, because you have his backstory rather badly wrong. Christopher Eccleston was never the first Doctor. He was always, from his first appearance identified as the Ninth Doctor. We now know that he was technically the tenth distinct incarnation of The Doctor, but since The Doctor does not consider the John Hurt incarnation to be "a Doctor", that one doesn't get a number. That makes David Tennant the Tenth Doctor, Matt Smith the Eleventh, etc. The Tenth Doctor, and his chief rival The Master, did frequently reveal parts of their childhood and history over the course of Tennant's tenure as The Doctor. However,
Cites Hypnosifl · 2015-07 · Science Fiction & Fantasy Stack Exchange · on “Why/When did the Doctor's regeneration process become dangerous to those around him?”
Finally, although we don't see the regeneration of 8 to the War Doctor full-on in The Night of the Doctor [this video] , we do see light begin to stream out of 8's body in exactly the same way as in 9 and 10's regenerations, and then they cut to a shot of one of the sisters who is suddenly illuminated by a bright flash. So that's consistent with the idea that his regeneration was probably about as energetic as 9 and 10's, even though he hadn't absorbed any large amounts of energy recently.