The original Rollerball (1975) is a fantastic dystopian science fiction film in which corporations run the world and crowds go crazy for an ultraviolent sport called, you guessed it, Rollerball. (Watch the movie trailer below.) Just before shooting wrapped up, the movie teams played the game for real (apparently with less blood) for an audience of thousands at Munich's Olympic Basketball Stadium. Sports Illustrated covered the chaos for its April 21, 1975 issue:
(Director Norman Jewison… was delighted that the game devised for his film turned out to be one that can be played in earnest. "It can be played, if it's played with very strict rules…" he said on the set. "But it is still a very violent game, though maybe no more so than football. There is a gladiatorial aspect to rollerball that frightens me."
"Rollerball" article from Sports Illustrated (via Reddit, thanks UPSO!)
