Now that the movie is out on DVD/Blu-Ray, I figure the easy way to satisfy curiosity is to simply post my screenplay from June 2005.
Quick history: This was the last draft I wrote, starting from the story John August and I pitched to Disney/Bruckheimer in 2004. A series of other writers took it from there: Jeff Nachmanoff, Boaz Yakin, Doug Miro & Carlo Bernard, in that order, resulting in the shooting script that went into production in summer 2008.
Update: If you’re curious about the game-into-movie adaptation process, I’ve also posted the original game script of Ubisoft’s Prince of Persia: The Sands of Time, which I wrote in 2002-03, and an accompanying article about how that game story was developed. As these materials illustrate, writing for games and movies are two very different crafts.