Doctor Who: 10 Things Everyone Always Gets Wrong About The TARDIS
8. The TARDIS Can't Be Invaded
“The assembled hordes of Genghis Khan couldn't get through that door, and believe me they’ve tried.“
That's what the Ninth Doctor says to Rose to reassure her of her safety once she's inside the TARDIS, but what's the most important rule in this show? The Doctor lies.
Though the TARDIS does have many systems that protect the Doctor and their companions - such as its shield which protects people within a few feet of the exterior, or Emergency Program One, which returns a companion home if the Doctor is in mortal danger - that doesn't mean it's an impenetrable fortress.
In fact, it's been shown that the TARDIS can be accessed by unsavoury forces quite easily, most recently during the Thirteenth Doctor's time, when the Kasaavin, the Judoon, and the Eternal Zellin managed to breach its walls.
A Kerblam robot managed this too, but we'll let him off the hook, because he was one of the good 'uns.
The sinister House even managed to steal the TARDIS' matrix without much effort, so perhaps the Fourteenth and Fifteenth Doctors should get to work on buffing their ship's defences?