Norman Jewison said he cast James Caan as Jonathan E, the champion Rollerball player, after seeing him play Brian Piccolo, the real-life Chicago Bears running back in Brian's Song (1971) (TV).
The game of Rollerball was so realistic the cast, extras, and stunt personnel played it between takes on the set.
There was only one "Rollerball" rink. It was redressed to appear as different cities.
During the Tokyo-Houston game, the Tokyo fans are chanting "Ganbare Tokyo!", which translates into "Let's Go Tokyo!"
Contrary to rumors, no one died during the filming of any of the stunts.
Some of the other "rollerball cities" mentioned in the movie: Madrid, Manila, Rome, Pittsburgh.
In the liner notes to the Region 2 DVD, director Norman Jewison is quoted as being influenced by Kubrick's A Clockwork Orange (1971). The influence is most obviously seen in the repetitive use of zooms, classical music and modern (i.e. concrete and glass) architecture.
This was the first film to give full screen credits to the stunt performers. Normally their work would go uncredited, but the director was so impressed by their work, he felt moved to include their names in the closing credits. Ever since, stunt performers have received screen credit for their work.
The game sequences were filmed in the Olympic Basketball Arena in Munich. Munich citizens were invited to the filming to serve as spectators to the games. Norman Jewison intended the movie to be anti violence, but audiences so loved the action of the game that there was actually talk about forming rollerball leagues in the wake of the film which horrified him.