‘Doctor Who’: How Many Times Can The Doctor Regenerate?

The 2017 “Doctor Who” Christmas special is going to be a big one, and it’s not just because this is the only episode of “Doctor Who” fans will get until next fall. It’s the regeneration that has fans excited, but as sci-fi fans often do, they’re arguing about how legitimate that is. After all, the Doctor is only supposed to be able to regenerate so many times.

“Doctor Who” replaces the Doctor every few years. After all, you can’t have a show run for over 50 years with the same leading actor. Peter Capaldi, the Twelfth Doctor, is stepping down, and Jodie Whittaker will be the first female to take over the TARDIS. While some fans argue that the Doctor shouldn’t be a woman, others don’t think there should be another Doctor at all on the BBC America hit.

Long ago, there was a rule introduced that the Doctor had 12 regenerations. So that would mean the Thirteenth Doctor would be the last. Though Capaldi is known as Twelve, he is actually the thirteenth incarnation. John Hurt’s War Doctor changed the order. That means Capaldi should be last, unless the rules changed.

It’s likely that “Doctor Who” tweaked the rules. In an episode of “The Sarah Jane Adventures,” the Doctor claims he can regenerate 507 times. In a 2014 episode called “Kill the Moon,” even the Doctor seems unsure of his ability to die. “You’ll have to spend a lot of time shooting me, because I will keep on regenerating. In fact, I’m not entirely sure if I won’t keep on regenerating forever,” he said.

Immortality would make sense since it doesn’t seem like we’re running out of Doctors anytime soon.

However, showrunner Steven Moffat, who will step down with Capaldi, claims that the rule of 12 regenerations is correct. “He can only regenerate 12 times,” Moffat said at a Radio Times event in October. “I think you should go back to your DVDs and count correctly this time. There’s something you’ve all missed.”

It’s possible that he is referring to Matt Smith’s regeneration. Due to a couple off screen regenerations, Smith’s Eleventh Doctor believed that he would be the last in “The Time of the Doctor.” However, he was given a “new regeneration cycle,” meaning that Capaldi’s Twelfth Doctor may have been the first regeneration in a new cycle of 12.

Fans will have to watch the Christmas special to see if Capaldi’s final episode addresses the regeneration count issue.

The 2017 “Doctor Who” Christmas special airs Monday at 9 p.m. EST on BBC America.