10 Times Doctor Who Has Broken Its Own Rules

10. The Rule Of Thirteen

A long-established Doctor Who rule is the Time Lord 'Rule of Thirteen' - that is, twelve regenerations, thirteen lives. A rule carried over from the classic series, modern Doctor Who has been playing hard and fast with it.

When the Doctor first appeared in his Ninth incarnation at the beginning of NuWho, without a regeneration from the Eighth, it wasn't before long that a secret Doctor was introduced to audiences. 2013 revealed a hitherto incarnation - known as the War Doctor - who had existed between the Eighth and Ninth Doctors.

When the Tenth Doctor regenerated for the first time in 2008's Journey's End, that was another regeneration used up. By the Eleventh Doctor's demise, he had apparently used up all of his regenerations and was on his last life.

However, a friendly deus-ex-machina in the form of a brand new regeneration cycle was granted to him by the Time Lords. This allowed him to regenerate into his Fourteenth and Fifteenth incarnations - the Doctors we refer to as the Twelfth and the Thirteenth.

However, this apparently wasn't the first time the Doctor had been awarded a new set of regenerations - if Series Twelve is to be believed. Introducing the 'Ruth Doctor' in 2020's Fugitive of the Judoon, fans have been scratching their heads deciding where she fits into the Doctor's already packed regeneration cycle.

Furthermore, The Timeless Children stated that the Doctor has regenerated possibly thousands of times before the First Doctor, but had their memory wiped. But how? What other rule-breaking deus-ex-machinas have occurred in Doctor Who's murky history?

Fans are just going to have to wait and see to find out how many other rules have been broken to satisfy these plot twists...