Wolfenstein
The "Wolfenstein" series of video games started with the 1981 stealth-adventure video game "Castle Wolfenstein". It was developed by American programmer Silas Warner, a pioneer in the early eras of video gaming, especially the stealth genre. It was published by his (then) company M.U.S.E. Inc. (Muse Software). The player controls an unnamed American prisoner of war as he steals war files containing information about secret German war plans while avoiding or sometimes killing guards, and tries to escape the fortified Nazi stronghold Castle Wolfenstein, set during World War II. The game is often credited as one of the first video games of the stealth genre, since it focuses more on avoiding or disarming enemies, and killing them is considered a last resort.
Wolfenstein 3D
"Wolfenstein 3D" was the second major release by id Software, after the "Commander Keen" series of episodes. In mid-1991, programmer John Carmack experimented with making a fast 3D game engine by restricting the gameplay and viewpoint to a single plane, producing "Hovertank 3D" and "Catacomb 3-D" as prototypes. After a design session prompted the company to shift from the family-friendly "Keen" to a more violent theme, programmer John Romero suggested remaking the 1981 stealth shooter "Castle Wolfenstein" as a fast-paced action game. He and designer Tom Hall designed the game, built on Carmack's engine, to be fast and violent, unlike other computer games on the market at the time. "Wolfenstein 3D" features artwork by Adrian Carmack and sound effects and music by Bobby Prince. The game was released through Apogee in two sets of three episodes under the shareware model, in which the first episode is released for free to drive interest in paying for the rest. An additional episode, "Spear of Destiny", was released as a stand-alone retail title through FormGen.