Doctor Who Hasn't Explained Why Thirteen's Clothes Regenerated When David Tennant Returned
One of the biggest traditions in Doctor Who lore is that the incoming Doctor actor enters the show wearing the clothes of their predecessor. Regeneration doesn't tend to affect the Doctor's clothes, but rather the biological components of the Time Lord's physiology. For example, David Tennant's very first Doctor Who appearance at the end of Doctor Who season 1, episode 13, "Parting of the Ways," has the Tenth Doctor dressed in the garments of Christopher Eccleston's Ninth. However, Russell T Davies temporarily shelves this piece of lore when Jodie Whittaker's signature costume transforms along with the Doctor to create Fourteen's outfit.
The surprising choice to regenerate the Doctor's clothes sparked much debate across the Doctor Who fandom, with the show's high-concept reputation suggesting the phenomenon would eventually receive an in-universe explanation. Disappointingly, so long after "The Power of the Doctor" aired, there's been no onscreen mention of how or why the Doctor's clothing was caught up in the Regeneration process.
Why RTD Chose Not To Show David Tennant In Jodie Whittaker's Doctor Who Costume
The moment may not have been officially addressed within the world of Doctor Who, but second-time showrunner Russell T Davies has made his reasoning for the decision known. Speaking with Doctor Who Magazine (via Independent) Davies spoke of the "delicate" scenario of dressing a man in women's clothes. He suggested that the transition from a female Doctor to a male Doctor created certain obstacles that he found simpler to circumvent than to address directly.
“With respect to Jodie Whittaker and her Doctor, I think it can look like mockery when a straight man wears her clothes. To put a great big six-foot Scotsman into them looks like we're taking the mickey.” Davies went on to say that his respect for drag culture also contributed to his decision to bypass the tradition of a post-Regeneration Doctor wearing clothes they technically never chose. One of his biggest concerns appeared to be that a high-profile show like Doctor Who would struggle to go under the radar with a moment that could be interpreted in a number of different ways.
The Best Way To Explain Doctor Who's Regenerating Clothes Plot Hole
Imaginations are left to wander concerning the canonical reason why Fourteen was forced into a wardrobe change, especially with Davies' comments suggesting there is no real explanation within the world of Doctor Who. However, there are a few different theories that could clear up the situation. Firstly, the Fourteenth Doctor isn't the first version of the Time Lord to enter the fray in an inexplicably new outfit. When William Hartnell's First Doctor regenerated into Patrick Troughton's Second, his clothes also changed.
This didn't happen again until Tennant's 2022 comeback. However, one of the harsh realities of Doctor Who's classic era is that the rules and conventions of regeneration hadn't yet been established, so this early piece of lore was likely unintentional. Early oversight or otherwise, it'd be short-sighted to ignore the fact that the Doctor's clothes have indeed regenerated before. So, perhaps regeneration always has a small chance of also affecting a Time Lord's clothes, and it just rarely happens.
Another Explanation for the Regenerating Clothes
Another possibility, which is arguably becoming a little too convenient, is that the Toymaker is responsible for the Doctor's regeneration quirk in "The Power of the Doctor." The game-loving member of Doctor Who's Pantheon of Gods freely admits in "The Giggle" that he has made a "Jigsaw" of the Doctor's history. From the Toymaker's perspective, this could also include the Doctor's present or even his future, and therefore be responsible for altering how Doctor Who's main character regenerates.
