Marine Doom

Marine Doom is a single-level PWAD for Doom II. It was designed for use by the U.S. Marines, but was made available for public download on March 21, 1996 by Sergeant Daniel G. Snyder.

In the game, a fireteam, comprising four Marines, is supposed to accomplish a specific mission, the default being the destruction of an enemy bunker, although other scenarios such as a hostage rescue in a foreign embassy can be designed. In order to allow coordination of their movements, these soldiers play on separated computers in the same room. The fireteam consists of a Team Leader, two riflemen, and one machine-gunner.

Marine Doom was later superseded by the completely homebrew game America's Army in 2002.

History
In 1996, General Charles C. Krulak, Commandant of the U.S. Marine Corps issued a directive to use wargames for improving "Military Thinking and Decision Making Exercises". He entrusted the Marine Combat Development Command with the task of developing, exploiting and approving computer-based wargames to train U.S. Marines for "decision making skills, particularly when live training time and opportunities were limited."

A group of U.S. Marine simulations experts originally led by Major Kirk Skinner, including Lieutenant Luis Velasquez and Lieutenant Scott Barnett as the project officers with Sergeant Snyder as one of the designers and modelers, in Quantico, Virginia of the Automated Information Systems Office, and later Marine Corps Modeling and Simulation Management Office (MCMSMO), obtained a copy of the commercial Doom, released in 1993 by Id Software, and used it to develop a simulation which focused on mutual fireteam support, protection of the automatic rifleman, proper sequencing of an attack, ammunition discipline and succession of command.

Their code was adapted for the commercial Doom II before its release, and requires a commercial copy of Doom II 1.9 to run.

Before its completion, their map was modified to work with Doom II v1.9.