text: Doom The first-person shooter version of deathmatch, originating in Doom by id Software, had a set of unmodifiable rules concerning weapons, equipment and scoring, known as "Deathmatch 1.0".
  Items do not respawn, e.g. health, armour, ammunition; however weapons had a fixed status as available to any arbitrary player except the player who acquired the weapon — i.e. the weapon did not in fact disappear as items do when picked up. The player who acquires the weapon can only collect it anew after respawning (this sometimes leads to lack of ammunition if a player survives long enough, eventually leading to one's death due to being unable to fight back)
  Suicide (such as falling into lava or causing an explosion too close to the player, or getting crushed by a crushing ceiling etc.) did not entail negative score points.
  Within months, these rules were modified into "Deathmatch 2.0" rules (included in Doom v1.2 patch). These rules were optional, the administrator of the game could decide on using DM 1.0 or DM 2.0 rules.
  The changes were:
  Picking up an object removes it from the map.
  Objects re-appear 30 seconds after being picked up and can be picked up by anyone; bonus objects which provide significant advantages (invisibility power-up etc.) re-appear after much longer delay, some of them may not reappear at all.
  Suicide counts as −1 frag.