D is a puzzle-adventure horror game developed by WARP and directed by Kenji Eno. It is the first entry in the D series and was first released for the 3DO in 1995, and later ported to the Sega Saturn, PlayStation, and MS-DOS. The story follows Laura Harris as she goes to investigate a hospital after learning her father went on a mass murdering spree and barricaded himself inside. The hospital morphs into a castle upon her arrival, which she must explore to find her father. The player controls Laura through CGI full motion video sequences, and must complete the game within two hours without a save function.