Christopher Guest The Princess Bride (1987)
Christopher Haden-Guest was born in 1948 in New York, the son of the British diplomat and life peer Peter Haden-Guest, 4th Baron Haden-Guest. He inherited the barony on his father's death in 1996 and now sits as a non-affiliated peer in the House of Lords, though he uses the title only in Britain. He trained at NYU's Tisch School and the Stella Adler Studio, joined the Lampoon Radio Hour and Saturday Night Live in the early 1980s, and co-wrote and starred in Rob Reiner's This Is Spinal Tap (1984) as lead guitarist Nigel Tufnel — the role that made him a film face.
Reiner cast him as Count Rugen — the six-fingered swordsman who killed Inigo Montoya's father and built the Machine — three years later. The casting is part of the long Reiner–Guest collaboration that runs through Spinal Tap into The Princess Bride and his own subsequent improvised features (Waiting for Guffman, Best in Show, A Mighty Wind, For Your Consideration).
The Machine and the duel
Rugen has limited screen time but two of the film's most-cited sequences. The Machine demonstration at beat 24 — Rugen describing his half-life's invention with the satisfaction of a craftsman, then setting the dial to one — works because Guest plays the bureaucratic pleasure of explanation rather than sadism.b24
"I've just sucked one year of your life away. I may one day go as high as five, but I really don't know what that would do to you. So, let's just start with what we have. What did this do to you? Tell me. And remember, this is for posterity. So, be honest. How do you feel?" — Count Rugen (Christopher Guest), The Princess Bride (1987)
The duel with Inigo at the climax is one of the most-cited revenge sequences in modern American film. Guest plays Rugen flushed and panicking — the academic who built the Machine has no answer to the man who has trained twenty years for this exact corridor. The wound exchange (Rugen cuts Inigo across the cheek, hand, and stomach; Inigo answers each cut with worse) is sustained through long takes that depend on both actors' choreography. (wikipedia)
The fake six-fingered prosthetic on Guest's right hand was a practical-effects glove. He has said in interviews that the glove fit poorly and required constant adjustment between takes.
The improvised-comedy career
Guest's directorial career — Waiting for Guffman (1996), Best in Show (2000), A Mighty Wind (2003), For Your Consideration (2006), Mascots (2016) — has built the most consistent body of improvised ensemble comedy in American film. He works with a stable rotating cast (Eugene Levy, Catherine O'Hara, Michael McKean, Parker Posey, Bob Balaban, John Michael Higgins, Jane Lynch) and shoots from outlines rather than scripts. The Rugen role is unlike that work — written, theatrical, sustained — and is the closest thing in his filmography to an unembellished classical villain.
"Christopher is one of the great comic actors of his generation. But what people forget is that he can play it absolutely straight. Rugen has no jokes. He's terrifying." — Rob Reiner, Vanity Fair (2012)