The Shakespeare Code apparent ontological paradox by inspiring Shakespeare to borrow phrases that the Doctor quotes from his plays. Examples of this include the Doctor telling Shakespeare that "all the world's a stage" (from "As You Like It") and "the play's the thing" (from "Hamlet"), as well as the name Sycorax from "The Tempest". However, when Shakespeare himself coins the phrase "To be, or not to be", the Doctor suggests he write it down, but Shakespeare considers it "too pretentious". In a different version of the joke, the Doctor exclaims "Once more unto the breach", and Shakespeare initially likes the phrase, before realising
The Shakespeare Code glimpsed for an inn named "The Elephant". This is the name of an inn recommended in "Twelfth Night". The three Carrionites allude to the Weird Sisters from "Macbeth" (which was written several years after the setting of this episode); like them, the Carrionites use trochaic tetrameter and rhyming couplets to cast spells. When regressing the architect in Bedlam, The Doctor uses the phrase "A Winter's Tale", whilst the architect himself uses the phrase "poor Tom" in the same way as the 'mad' Edgar in "King Lear". Lilith credits the Carrionites' escape from the Eternals' banishment to 'new...glittering' words. Shakespeare is