Westworld (1973)

Westworld is a futuristic theme park where paying guests can pretend to be gunslingers in an artificial Wild West populated by androids. After paying a sizable entrance fee, Blane (James Brolin) and Martin (Richard Benjamin) are determined to unwind by hitting the saloons and shooting off their guns. But when the system goes haywire and Blane is killed in a duel with a robotic gunslinger (Yul Brynner), Martin's escapist fantasy suddenly takes on a grim reality.