Terry Nation, who penned the first story "The Daleks" in 1963, was given an on-screen credit at the end of all four episodes of this story as having originated them. The production team only had three Dalek props available for use during the production of this serial, so only three Daleks appear on screen at any one time. One of the Daleks is painted gold, so only two regular casings are seen in shot. Film editing is used to attempt the illusion of more than three Daleks. The final battle at Auderly House was disliked by viewers, as it was quite obvious that only three Daleks were attacking. On the 2011 DVD release, CGI was used to revamp the scene, making it appear that more Daleks were attacking the house.