Abnormality 0001

Abnormality Surname: Phantom Players

Risk Level: Passive

Status Level: Active

Type: Event

Abnormality #0001, unofficially dubbed "Phantom Players," is a persistent hallucinatory phenomenon encountered across a variety of legacy GMod maps, most commonly variants of:
Gm_construct
Gm_flatgrass
De_chambers (Community made map, removed in 2015)

The abnormality is not bound to any specific addon or file. It "overlays" visual and auditory distortions onto the player's perception of their environment while in singleplayer or small peer-hosted multiplayer sessions. These distortions include:
0001-A: Shadow players walking in the peripheral vision of the player.
0001-B: Props appearing only in screenshots and not during gameplay.
0001-C: Strange ambient sounds playing around the map.
0001-D: Fake players appearing on the leaderboard for brief seconds.

First widely reported in August 2016 after user nervetear uploaded a playthrough of gm_construct where props seemed to rearrange themselves off-screen. Commenters noted the appearance of a second player reflection in the window above the spawn garage. Video was titled "I didn't add this," later removed.

Screenshot of Instance 0001-A appearing in a singleplayer session