An enemy's line of sight or field of vision is the area in which an enemy can see the player and commence their attack.
The fields of vision for various enemies are listed below:
- A seeker drone's field of vision consists of four straight lines extending up, down, left and right from the drone itself, which continue until contacting any tile other than the blank 'E' tile, or a closed door of any kind.
- Chaingun drones, laser drones, gauss turrets, and homing missile launchers all have a 360° view of their surroundings, which continues until blocked by doors or tiles.
- A floorchaser's field of vision consists of two straight lines extending left and right from the floorchaser, which continue until contacting any tile other than the blank 'E' tile. Note that floorchasers can see through all three door types.
- A thwump's field of vision consists of three straight lines: one extending from the thwump itself and continuing in the direction the thwump is facing until contacting a door or a tile, and two parallel ones that extend from one tile space perpendicular to the thwump's direction on either side until it reaches either a door or a tile, or until it reaches the same place where the central line of sight. In other words, standing a tile away from a thwump's central line of sight will activate it, but will not harm the player.