Obviously the audition process for the role of the 12th Doctor on Doctor Who was never going to be basic. Showrunner, Steven Moffat really threw Peter Capaldi through the ringer.
During the live telecast, Peter Capaldi stated that he tried to prepare a bit for his audition by downloading some classic Doctor Who scripts from the Internet and practicing them before the mirror. Capaldi further revealed that despite his preparation, that it didn’t help at all. Now we know why.
For many TV series you end up putting yourself on DVD reading a scene and shipping it to a casting director. Other times you come in, read a brief scene, answer a few questions, maybe read again with some direction, and out the door you go.
The thing is, Doctor Who isn’t most series. As far as intricacy of language it’s probably up there with medical dramas, only with medical dramas the words actually could be found in a medical dictionary – and have some basis in reality. Steven Moffat wanted to be sure that the next Doctor was fully prepared for what the show involves each and every episode from impossible language to explosions and more.
According to Digital Spy, Moffat attested to Capaldi’s skills at the audition from hell:
I’ve seen him do ‘Doctor-ish’ stuff and it’s worked. I’ve seen him deal with the technobabble, I’ve seen him deal with the nonsense…I wrote scenes that were deliberately impossible – deliberately impossible dialog, just to see, ‘Can you do the impossible, even without gunk being poured on you?’ and now we’re going to pour gunk on you, and throw a lizard at you, and ask you to say all this stuff and explain the plot…
When questioned further about Capaldi’s readiness for such a physical role, Moffat stated, “I can somehow absolutely believe that the strange old/young Matt Smith will turn into the strange young/old Peter Capaldi.”
Given what happened, it’s a wonder Capaldi didn’t run screaming out the door asking for his union rep. It certainly attests to Capaldi being a good sport and a consummate Doctor Who fan to get it all right, and to want to tackle all of that for 13 episodes a year plus a Christmas special.