Whovians across the ‘verse are familiar with Regeneration, the most brilliant way to replace your lead ever devised. Regeneration is a biological process that allows a dying Timelord to change physical form which brings about new behaviors or it can be seen as how the show replaces the actor portraying the Doctor. Since 1963, eleven different, yet same, Doctors have traveled in the TARDIS having adventures and thrilling us all. Some fans of the series have expressed concern about the future of the show since Timelords only have twelve regenerations. This means only two more actors will play the Doctor and the series will come to an end. That would be true except the regeneration rules are more fluid than most fans realize.
Doctor Who premiered in 1963 with William Hartnell playing the madman with a box. After three years it became apparent that Hartnell’s health would not allow him to continue to portray the Doctor. Script editor Gerry Davis suggested that, since the Doctor is an alien, he could “die” yet return in a new body. The second incarnation, Patrick Troughton, described this as ‘rejuvenation’, that is a function of the TARDIS. He goes on to tell his companions this change is like a caterpillar becoming a butterfly. Viewers learn later on that the TARDIS does help with the regeneration process.
In 1969 Troughton exited the role and John Pertwee became the new Doctor. This “change of appearance” was forced on the Doctor by the other Timelords when they finally caught up with the on-the-run renegade. The process is still shrouded in mystery at this point. In fact, it would not be until Planet of the Spiders, when Pertwee is replaced by Tom Baker, that the term “regeneration” is even used. It is also interesting to note that this episode showed the Doctor receiving help from another Timelord to regenerate as his own body because of the radiation of the Metebelis crystals.
It is during the Doctor’s fourth incarnation that the “rule” of twelve regenerations is established in the Manchurian Candidate inspired eppy The Deadly Assassains. This episode also features the Master searching for artifacts of Rassilon to obtain a new cycle implying the limit of twelve is not set in stone. The fourth Doctor gained a Time Lady companion named Romana who put a new spin on regeneration when she not only imitated her own change but also “tried on” several bodies of alien form before deciding on a humanoid form in Destiny of the Daleks. Not all regenerations go well as learned in The Brain of Morbius when it is revealed that the Sisterhood of Karn had spplied the Timelords with an “elixir of life”.
The eppy Logopolis features a future version of the Doctor known as The Watcher. While the Doctor lays dying, The Watcher “merges” with him and the regeneration process occurs. This would mean that one of the last two regenerations would have to be The Watcher. The fifth Incarnation (Peter Davison) tenure changes the view of regeneration and nowhere more than in The Five Doctors in which all five of the Doctor’s incarnations are trapped in the Death Zone. In an effort to save the Doctor, the Timelords offer the Master a new regeneration cycle if will help his nemesis. Although the fifth Doctor states outright in Mawdryn Undead that he has eight future selves left, the classic series clearly shows that the regeneration rule is flexible at worst. This eppy also introduced the idea that regenerations could be transferred which is rather important as I hope to explain in just a bit. .
The new series, a term that I have learned to deal with, offers more proof that 13 is not the magic number for the Doctor. In The Sound of Drums the Master tells the Doctor the Timelords gave him a new cycle when they enlisted his aid in the Time War. This makes the second time the Master was given such an offer that we know of. River Song/Melody Pond complicates the matter further. In Let’s Kill Hitler we learned that River can regenerate. In fact, she is the little girl who regenerated in Day of the Moon. River/Melody was given this ability by her time in the TARDIS while waiting to be born when Amy Pond was traveling with the Doctor. River Song dies in Silence in the Library as the version of herself that viewers are most familiar with. If she has twelve regenerations then she might have passed her remaining ones to the Doctor when healing him in Let’s Kill Hitler, then that would allow the Doctor to have more than thirteen incarnations.
The final thing to consider is the Time War itself and the Doctor being the only survivor, well only that he knew of. The Timelords have the ability to give others new cycles. Even if this is only true of the Gallifreyan high council, the Doctor *is* the Gallifreyan high council. (He is also the President and has been twice, but that is another story entirely.) The new series has done nothing to indicate the “rule” is still in effect. In fairness, The Sarah Jane Adventures reminded us all that thirteen was the number in Death of the Doctor but a clear answer was not given. As the last of the Timelords, the Doctor may well have control over how many regeneration cycles he has left. All of the other responsibilities are now his, doling out more life could easily be one as well.
At some point the show is going to have to answer the question of thirteen lives for the Doctor. It could be circumvented by River’s transfer of energy, the Doctor being the only Timelord left, or any other plot device the writers come up with. No matter what the answer is going to be, the “rule” will be changed. Rules are made to be broken and no one has broken more than the Doctor has. That is one of the reasons we keep watching. He has gotten out of so many impossible situations that living longer does not seem to be that difficult for him. Besides, if thirteen is the magic number the show will have to end and no one wants that. As long as we keep watching the Doctor will keep travelling.