

In Doom and Doom II, the player stands for an unnamed battle-hardened marine sent to Mars for a violent response against an irresponsible commander (see Doom's protagonist), while in other Doom engine based games it is a particular character fitting the corresponding background story.

The player's sprite looks like a green armored space marine, holding an assault rifle and wearing a helmet. Because every character, including the player is made of sprites, a player can't see the other player's real weapon. Since the game is played from a first person perspective, a player does not see his or her sprite on the main portion of the screen, except for a hand or two when certain weapons are selected or used. The entity has various attributes, such as a position on the map, health, and items possessed which vary according to the user's actions within the game levels. The player (or the space marine or Doom's protagonist) is the entity or thing in the game controlled by a person playing the game (the player as an individual, or the game user), either alone, or as one of several in multiplayer mode. One player in Doom looking at two others, Brown and Indigo, on the starting alcove of Level 1: Entryway, in Doom II.
