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), 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 a fairly simple textbook raycaster, using maps composed of tiles, which only allow 90-degree angles between walls. While walls are textured, horizontal planes forming the floor and ceiling are shaded with flat colors. 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, Operation Bodycount, and, which enhance the engine with numerous features, some similar to those id Software added to Doom such as textured planes, distance shading, teleporters and switches.

The game data is spread across four files (,, , and ) with four additional files (, , , and ) containing metadata such as offset positions, size, and compression dictionary allowing to actually retrieve the game data. The file names are hardcoded, but the extension varies depending on the game &mdash; for the shareware,  for the registered game,  for the full game with the added "nocturnal missions",  for the Spear of Destiny demo, and  for the full Spear of Destiny game. Each data blob is referenced in the executable by its hardcoded index position, rather than by a lump name; and since different versions of the game have different amounts of game data, the offsets change for each version. This design has two consequences: it is not possible to replace only one part of the resources from one data file, all the other resources need to be included as well; and in addition each version of the game needs its own executable. Playing a mod involves replacing the relevant data files by the modded ones.

Despite these hurdles, a Wolfenstein modding scene emerged fairly quickly, and because of them many mods had to be essentially stand-alone games that did not require the player to actually own the games before they can play them, a practice to which id Software naturally objected. The WAD format used in Doom was intended to resolve these problems: identifying resources by lump names allow to simplify the engine considerably by not having to maintain different index lists for different versions, which also allows to have the same executable running all versions of all Doom IWADs, and it also makes modding much easier by allowing to put all data in a single file whose content can override that from the main game file without having to replace it.

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 on a technical level 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

 * The style of game divided in episodes is very similar to Wolfenstein. Initially, Wolfenstein had three episodes, each with nine levels and a secret level. Later on, the expansion pack "The Nocturnal Missions" with three new episodes was added. Doom had three episodes originally, with eight levels and a secret level each, and an expansion pack with a new episode was also released. Both games have a boss at the end of each episode. Both shareware versions include only the first episode.
 * The first episode of Doom contains only a couple of weak opponents, and in the end there is a boss that is supreme in comparison with them. This resembles Wolfenstein's gameplay style. However, later episodes of Doom include more powerful weapons and enemies, and the bosses are much more powerful than any enemy.
 * The second Wolfenstein game, Spear of Destiny, includes 19 new levels and two secret levels in a single campaign, and the episode select screen was removed. Doom II was released in a very similar way.
 * The status bar has the same style, including displays for health, ammo and keys. Early versions of Doom included displays for score and lives, and the selected weapon was also illustrated in the bar.
 * The supercharge power-up in Doom resembles the extra lives in Wolfenstein.
 * The status bar face is very similar to the one in Wolfenstein, including a grin face when the player picks up the chaingun. Spear of Destiny also had an Ouch Face and the face has golden eyes in god mode.
 * Wolfenstein has three weapons, the pistol, the machine gun and the chaingun, all which use the same ammo. Doom still kept the pistol and chaingun. However, instead of the machine gun, it included the shotgun which used a different set of ammo.
 * The ammo clip sprite of Doom is similar to that of Wolfenstein, and is also dropped by the most common type of enemy.
 * The Doom demons act almost exactly like the Wolfenstein dogs.
 * The chaingunner is somewhat reminiscent of the first Wolfenstein boss, Hans Grosse.
 * The chaingun carried by the Wolfenstein bosses looks similar to the spiderdemon's chaingun. The most clear similarity is that they both have six barrels.
 * The rocket launcher carried by Otto Giftmacher and General Fettgesicht fires similar homing missiles to those of the revenant's, complete with smoke trail.
 * Similar to Wolfenstein 3D, Doom has a particular door texture used for the start area and the final room.
 * Excluding the textures used in the two secrets level in Doom II, the following flats and patches are ripped or based on Wolfenstein 3D walls:
 * FLAT1_1 and FLAT1_2
 * FLAT5_7 and FLAT5_8
 * GRNROCK, RROCK13, RW30_1, RW30_2 and RW30_3
 * RROCK11 and RW1_1
 * RW35_1 and RW35_2
 * RW41_3 and RW41_4

Homages in Doom engine games

 * 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 Grosse, the player encounters Demons, the SS Nazi troopers, and a Cyberdemon respectively. The secret levels also include music from Wolfenstein 3D and Spear of Destiny.