Deathtag

Deathtag is a team multiplayer game type requiring four players that was created by Lance Lancaster (Aikman) and Craig Wessel (Talon). It requires a custom community-made level and it can run in vanilla Doom deathmatch mode without the need for a source port. The game type predates the influx of multiplayer ports such as Zandronum.

Gameplay

 * Two multiplayer teams of two
 * One player goes to the enemy base while the other stays at the radiation suit door.
 * The player in the enemy base hits the switch which unlocks the radiation suit in your own base.
 * The player who gets the radiation suit will teleport to the enemy base, and they must run to the scoring line.
 * The first team to score five times wins.

Color-coded team scores are shown on custom wall textures that update each time the scoring line is reached. When a winner is declared, teams can then restart the level or exit to the next level.

Level technical requirements

 * Two sets of two deatchmatch starts to form two teams with player pairs.
 * Each team has a unique scoring linedef trigger surrounded by a 20% damage sector type. This area should be large enough that a radiation suit is required to survive reaching the scoring line.
 * The scoring area is accessed by one player hitting a switch to open a repeatable door for their teammate.
 * The opened door gives the second player a radiation suit and immediately teleports them to the damaging scoring area.
 * Reaching the scoring line increases the team's score by one.

Notable levels
There are a limited number of levels that support deathtag as the Doom community generally played the two initial WADs created by Aikman and Talon. More levels supporting this mode can be found in the deathmatch directory on the idgames archive.

1995

 * by Lance Lancaster (Aikman) and Craig Wessel (Talon)
 * by Lance Lancaster (Aikman) and Craig Wessel (Talon)
 * by Lance Lancaster (Aikman) and Craig Wessel (Talon)

1997

 * by Tom Mustaine and Josh Martel (Null)
 * by Tom Mustaine and Josh Martel (Null)

2002

 * from the Unidoom DM (series)

Trivia

 * In 2000,  designed and produced by John Romero was the first commercial game to have deathtag mode included.