Aimbot

An aimbot is a multiplayer cheat which causes the cheating player to automatically center the opponent on the screen.

Aimbots are considered unfair, as they enhance player aim abilities through an automated means to a level of accuracy that is not humanly executable. Also, they may provide means to locate opponents that are not normally visible (because the cheating player is able to automatically face the opponent, regardless of walls separating them or distance from one another).

Implementation of aimbots usually involves a replacement Doom executable file or a TSR program. Detection of involves either analysis of the recording file (.lmp), or visual observation.

Source

 * This writeup includes text from The autoaim cheat for Doom2 1.9, used with permission.