GURPS creator Steve Jackson Games. According to Interplay, Steve Jackson objected to the amount of violence and gore. Interplay was forced to change the GURPS system to the internally-developed SPECIAL system; Taylor and Cain were each given a week to design and code it, respectively. Concept and influences Prior to the license's termination, the engine for Fallout was based on GURPS. Fantasy and time-traveling settings were considered before the development team decided on a post-apocalyptic setting. Taylor outlined the design goals in a vision statement, which Cain called an inspiration for the development team and "a major reason why the game came together at all." Fallout was a spiritual successor to Interplay's role-playing video game Wasteland (1988), published by Electronic Arts. Almost everyone who worked on Fallout had played it. The team was unable to make Fallout a direct sequel to Wasteland because Electronic Arts refused to license it. The team drew inspiration for Fallout retro-futuristic art style from 1950s literature and media related to the Atomic Age. Especial influence came from the 1956 science fiction novel Forbidden Planet and optimistic Cold War posters, which Boyarsky reportedly loved. The vaults were influenced by the underground base in the science fiction movie A Boy and His Dog (1975). Cain said that the team "all loved X-COM" and that Fallout featured combat similar to X-COM prior to the GURPS license. Cain admired Star Control II (1992) and said it influenced Fallout open-ended design. Fallout features many popular culture references. The team was only allowed to include references if understanding the source material was not required for the reference to make sense. For example, the Slayer perk's name references the television series Buffy the Vampire Slayer while generically matching its effect (turning all attacks to critical hits). Characters and writing The sprites in Fallout were highly detailed and took up a huge chunk of memory. 21 NPCs were voiced by various actors, and Ron Perlman voiced the narrator. Some NPCs feature 3D models during conversation called "talking heads", most of which were created by Scott Redenhizer. Each took eight weeks to create, and voice recording took a few months. The talking heads began as sculpted heads of clay, which the team studied to determine which parts should be most animated. The heads were digitized using a Faro Space Arm and VertiSketch, with LightWave 3D used for geometric corrections and the texture maps created