Partial invisibility



A blur artifact (also known as an invisibility sphere or partial invisibility) is a powerup that appears as a floating red orb with a blue eye-like pattern. Picking one up will grant the player temporary partial invisibility. The player's sprite (as seen by other players in multiplayer mode) will be given a filter similar to that of the spectre, while the affected player will see their own weapon and hands as partially invisible. When 5 seconds remain, the weapon will begin blinking, signaling the end of the artifact's effects; the player's sprite, however, remains filtered until all 60 seconds have expired.

Monsters firing upon an affected player will have their accuracy reduced, in that their aim is offset by a random angle, causing them to miss more often. This, however, may cause more experienced players who are accustomed to monsters firing directly forwards to inadvertently dodge toward incoming projectiles rather than away from them. Nevertheless, a blur sphere bestows an advantage against long-range hitscan attacks such as those of zombies or Spider Masterminds. On the other hand, the invisibility is unable to disrupt monster melee or Arch-Vile attacks (even though the monsters do appear to spin around in confusion).

Partial invisibility can also be invoked with the cheat code idbeholdi.

In deathmatch mode of vanilla Doom, blur artifacts and invulnerabilities never respawn. Some source ports allow flags to be set to allow them to respawn. Also, deathmatch players should remember that using weapons with visible projectiles (particularly the plasma rifle) can give a partially-invisible player's position away, as the opposing player can target the shots' point of origin even if the player themselves is very difficult to spot.

Blur artifacts are included in the items percentage displayed at the end of each level.

Appearance statistics
The IWADs contain the following numbers of blur artifacts: