Wolfenstein 3D

Wolfenstein 3D (also written Wolfenstein 3-D) is a first-person shooter created by id Software and published by Apogee Software in 1992. It involves the adventures of an Allied soldier, B.J. Blazkowicz, fighting his way through a series of Nazi dungeons during World War II. It owes much of its success to an aggressive shareware marketing campaign which was later repeated with even greater success for Doom. It also spawned a commercial prequel, Spear of Destiny, which used the same engine. Since then several Wolfenstein games have been made on newer tech.

Inspiration for this game came from the even older 2D games Castle Wolfenstein and Beyond Castle Wolfenstein, published by Muse Software. Unlike these predecessors, Wolfenstein 3D shifted the focus away from puzzle solving in favor of more action-oriented gameplay. Though id had planned to include more strategic elements seen in these earlier games (such as wearing captured uniforms and dragging bodies), they came to feel these features made gameplay too complex, slowing the action down. The final release did retain some arcade-style concepts, such as lives and scoring.

Technical
The engine is fairly simple, using maps composed of tiles, which only allow 90-degree angles between walls. Planes are shaded with flat colors instead of having textures. Much of the source code for Wolfenstein 3D was later reused in Apogee's Rise of the Triad, released in 1995. Like the Doom engine, the Wolfenstein 3D engine was also used for several other games; Blake Stone: Aliens of Gold, Blake Stone: Planet Strike, Corridor 7: Alien Invasion, and Operation Bodycount, which enhance the engine with numerous features, some similar to those ID added to Doom such as textured planes, distance shading, teleporters and switches.

Fanbase
At the time of its release, Wolfenstein 3D was seen as a revolutionary new product, and is regarded by many to be the grandfather of all FPS games, as it popularized the genre tremendously. It is especially noteworthy for having directly led to the development and publication of Doom just a year after its release. Although Doom and its successors quickly superseded Wolfenstein to become an equally important milestone in the development of the first-person shooter, Wolfenstein still enjoys a substantial following on the Internet, including websites, user-created maps, and even totally new games based on the source code, which was released on July 21, 1995.

Similarities with Doom engine games

 * Wolfenstein's style of dividing the game into episodes is very similar to Doom's layout. Wolfenstein had 3 episodes, each comprised of 9 levels (plus 1 secret level), while the "The Nocturnal Missions" expansion pack added 3 further episodes. Doom had 3 episodes, each containing 8 levels (and 1 secret level), with an expansion pack comprising 1 new episode released later. Both games featured boss battles at the end of each episode. Additionally, the shareware versions of both games included only the first episode.
 * The first episode of Doom features limited numbers of very weak opponents, and the episode's end boss has 1,000 hit points; this resembles Wolfenstein's gameplay style. However, later episodes of Doom included more powerful weapons and enemies, and the concluding bosses were significantly more powerful than any regular enemy.
 * The second Wolfenstein game, Spear of Destiny, included 19 new levels (and 2 secret levels) in a single, continuous campaign, and the episode select screen was removed. Doom II featured a similar structure, though a second campaign, No Rest for the Living, was added to official versions in 2010.
 * Both games use a status bar, including a health, ammo and door key display. Early versions of Doom included a score, remaining lives and weapon display, like Wolfenstein.
 * Doom's status bar face is very similar to the one in Wolfenstein, including a grin when the player picks up a new weapon. Spear of Destiny also added an ouch face.
 * Wolfenstein offered the player three guns - the Pistol, the Machine Gun and the Chain Gun, all of which used the same ammo. Doom kept the Pistol and the Chaingun, but replaced the Machine Gun with the Shotgun, which used a different type of ammunition.
 * The ammo clip in Doom is similar to that found in Wolfenstein, and is similarly dropped by the most basic class of enemy.
 * Several enemies are very similar. Doom's Former Human resembles Wolfenstein's Guard; both are the weakest opponent in their respective games, and the weapons they use (the rifle and the pistol respectively) are also very similar in function. Doom's Demon behaves almost exactly the same as Wolfenstein's Dog. Doom II's heavy weapon dude vaguely resembles Hans Grösse.
 * The super chaingun used by the Spider Demon in Doom looks and behaves similarly to the chainguns used by bosses in Wolfenstein.

Homages in Doom

 * The swastika room of E1M4: Command Control (removed in version 1.4 and subsequent revisions).
 * The SS Nazi monster, based on the same enemy in Wolfenstein 3D.
 * The two secret levels, which are recreations of E1L1 and E1L9. Instead of attack dogs, brown-uniformed foot soldiers, and Hans Grösse, the player encounters Demons, the SS Nazi troopers, and a Cyberdemon respectively. The secret levels also include music from Wolfenstein 3D.