In the first Indiana Jones film, “Raiders of the Lost Ark,” there is a scene in which a swordfighter in a market confronts Indy and shows off with some fancy sword menouvers. Indy’s solution is to pull out his gun and shoot him. This was improvised by Harrison Ford, who had an upset stomach on that day of shooting and asked the director if he could cut the originally-planned long and drawn out fight scene shorter. The director agreed, but didn’t tell the rest of the cast or the filming crew, as a joke. Turns out to be one of the most popular scenes in the film.