In techniques for computer games, fixed 3D refers to a three-dimensional (3D) representation of the game world with game characters rendered in real time against a pre-rendered environment.

Used heavily in the survival horror game genre, it was first seen in Delphine's Alone In The Dark series in the late 1980s; it was later revived and bought up to date by Capcom in the Resident Evil series.

Other notable examples include

Admittedly, there seems little to separate fixed 3D from its precursor, the graphic adventure game (Monkey Island, Sam and Max etc.), but whereas the latter overlays 2D characters over a 2D background, fixed 3D is at least 3D overlaid on 2D, and often onto 3D.