Codex Gamicus

Shadow Warrior is a first-person shooter video game developed by 3D Realms and published by GT Interactive Software. The shareware version was released for DOS on May 13, 1997, while the full version was released on August 31, 1997. Shadow Warrior was developed using Ken Silverman's Build Engine and improved on 3D Realms' previous Build Engine game, Duke Nukem 3D. Mark Adams ported Shadow Warrior to Mac OS in August 1997.

The game's improvements included introduction of true room-over-room situations, the use of 3D voxels instead of 2D sprites for weapons and usable inventory items, transparent water, climbable ladders, and assorted vehicles to drive (some armed with weapons). Although violent, the game had its own sense of humor and contained some sexual themes. A combination of Shadow Warrior and Duke Nukem 3D: Atomic Edition was published by GT Interactive Software in March 1998, titled East Meets West.

In 2005, 3D Realms released the source code for Shadow Warrior (including compiled Build engine object code) under the GPL, which resulted in the first source port a day later on April 2, 2005. In 2013, Devolver Digital announced the game would be free to obtain for a limited time on Steam. Later, Devolver Digital announced that they would permanently offer the game for free.

A remake, also titled Shadow Warrior, was developed by Flying Wild Hog and published by Devolver Digital, and released on September 26, 2013.