Alpha

Before the release of the final game, there were three alpha versions of Doom released, and one beta version.

Doom 0.2 (February 4, 1993)

 * Main article: Doom 0.2

This early version demonstrates three of the main technological advances in Doom: texture mapping, variable light levels and non-orthogonal walls. The player can move around a small, completely flat level and press keys to change the light level and the textures. The Imp, Demon and Baron of Hell monsters are in place, but do not act or interact with the player. The heads-up display (HUD) is more complex than in the final game, including a small automap view and what appears to be a display for messages from other player characters; it is however, non-functional. The HUD also lists three items: "Captain's hand", "Heart of Lothar" and "Sandwich", items from Tom Hall's design document for the game.

Doom 0.4 (April 2, 1993)

 * Main article: Doom 0.4

Many level structures from the final game are recognizable, but have significantly different textures and/or differences in layout. Lifts do not move. The enemies still do not attack. The player has a rifle which can be fired.

Doom 0.5 (May 22, 1993)

 * Main article: Doom 0.5

More levels are present. Notably, a version of MAP10: Refueling Base from Doom II is present as the sixth level. Platforms now move, and doors can be opened. The player can take damage from slime, and can die. Various items are present, and can be picked up. Health kits will heal the player, and use the graphics from Wolfenstein 3D. Ammo clips will give ammo. Keycards and bonus (point scoring) items are also present. The monsters still cannot attack; they disappear when shot. The player now has a rifle bayonet as a melee weapon, in addition to the rifle itself.

Doom press release beta (October 4, 1993)

 * Main article: Doom press release beta

Functionally fairly close to the commercial release, with three levels. The plasma rifle fires red shots as well as green shots. The BFG fires many such shots in a wide field in front of the player, instead of the large plasma ball and invisible rays of the final version.