Ben Barnes (Logan) broke his foot before arriving to the first day of shooting. Being afraid of losing the job, he didn't tell anyone, and just used the limp to look like a character choice. He then had to maintain the limp throughout filming.
The quote "These violent delights have violent ends" is from Shakespeare's Romeo and Juliet.
The modern songs heard on the player piano in the Mariposa Saloon and Hotel are the idea of writer, producer, and director Jonathan Nolan. Nolan and composer Ramin Djawadi explained that the covers are to remind people that the world is a theme park, and that everything is scripted. The songs are chosen by Nolan.
Writer, producer, and director Jonathan Nolan describes this show as "the next chapter of the human story, in which we stop being protagonists."
In one scene, a character refers to the only "rule" of Westworld being that you cannot die. The name of the company that runs Westworld is "Delos", which is also the name of a Greek island, known for the earliest case of "Prohibition of Death", a political social phenomenon and taboo, in which a law is passed stating that it is illegal to die.