When Alec Guinness was asked to reprise his “Star Wars” role as Obi-Wan Kenobi in “The Empire Strikes Back,” he only agreed to do it under very specific circumstances.

Guinness would only shoot for one day: He would start at 8:30 a.m. and leave set by 1:00 p.m. If the “Empire” team didn't get everything they needed during that time, then too bad.

While on set, Guinness shot his ghostly reappearances as Obi-Wan telling Luke to seek out Yoda and talking with Luke on Dagobah, imploring the young Jedi not to confront Vader.

For his half-day of work, Guinness demanded a quarter of a point of the film's gross. For every four dollars “Empire” made, he got one penny, including box office and home video.

0.25% of a point of the film’s gross may sound very small, but with a franchise as massive as “Star Wars,” that quarter of a point turned into millions of dollars for Guinness.