"The key to Varys is that he's one way in public, when he's working, very fey, giggly, and effete for want of a better word, but there are moments when he drops all that and speaks honestly. That stuff is great to play. When Ned asks Varys who he truly serves, and Varys answers, "The realm," I think that's true. There's a moral code there... He sees in Tyrion someone who plays the game well, and Varys loves playing the game. Ned was too honorable and too good - he disdained the game."
In Game of Thrones, Hill is playing the role of Varys. He was confirmed in the role on 15 July 2010. He initially appeared as a guest star in the first season and joined the starring cast for the second season. He also voices the character of Varys in the Game of Thrones role-playing video game.
Conleth Hill originally auditioned for the role of King Robert Baratheon before being cast as Varys.
George R.R. Martin has repeatedly praised Hill's performance as Varys, citing him as one of the actors who comes the closest to exactly how he mentally pictured a character in the novels. As Martin explained, he his own image of the characters and their mannerisms in his head for nearly 20 years before the live-action series began, and while he certainly enjoys the performance of many actors (even Sean Bean as Ned Stark), few of them come close to exactly how he pictured them acting in his mind.