Brad Wright:(On how much actors ad lib on Stargate SG-1)I would say a great deal. Certainly Rick (Richard Dean Anderson) as executive producer will often ad lib or change dialogue to suit the scene. But we almost always agree with those changes, and I, for one, think the actors make our scripts better. We have read-throughs with every episode so that we may discuss every scene and make the script as good as possible before we begin shooting. All of our actors take their characters very seriously so that when they have concerns we listen.