It’s been about a year and a half year since we last saw Tywin Lannister on Game of Thrones (if you don’t count his funeral scene last season) and Charles Dance, who played the role, admitted that he initially didn’t know about his ‘spectacular’ death on the show.
“I knew his demise was coming but I didn’t know how. I didn’t read the books. They are far too thick. They frighten me books that thick…and we weren’t shooting books we were shooting very good adaptations by David [Benioff] and Dan [Weiss].”
It is quite normal for actors who feature in TV shows/movies based on already published material to avoid as much information as possible about their characters because it affects their acting. Tywin Lannister was in privy, when he was shot dead with a crossbow by Tyrion in Season 4 finale and Dance was not so fortunate in avoiding that information as a fan spoiled it for him.
“There was a guy in the street who came up to me and said ‘Game of Thrones, brilliant, you’ve got a great death scene’. And I said, ‘oh do I?’ He told me the manner of my death so I went into Waterstones, got the book and saw, ah on the khazi. Right. OK. Suitable demise, I thought.”
Dance revealed this in another interview as well, back in 2012, when his character was very much alive. You can see the video below.