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

Used heavily in the survival horror game genre, it was first seen in Infogrames' Alone in the Dark series in the early 1990s; it was later revived and bought up to date by Capcom in the Resident Evil series.

Other notable examples include

• Final Fantasy VII (Squaresoft)
• Mario Party series (Nintendo)
• Blade Runner (Westwood Studios) - apparently the backgrounds are rendered in real time, using millions of polygons, although this is difficult to tell
• Ecstatica and Ecstatica 2 (Andrew Spencer/Psygnosis) - unusual in that the backgrounds and characters are rendered with ellipsoids, leading to a very natural looking set of creatures. Like Blade Runner, it again is rendered entirely in real time, although it is difficult to tell at first sight
• Legend of Zelda: Ocarina of Time (Nintendo) - dropped for complete 3D in its successor, Legend of Zelda: Majora's Mask, 2D is used for many of the building interiors and for an entire town.

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.