Uploaded December 2025 | Updated September 2026, 1 week ago

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Shows that a specific Demon in the Refinery level of Doom/Ultimate Doom won't react to a player on the other side of an open doorway, unless the Demon has already heard the player or was otherwise awakened from its initial 'Wait mode' state. This is caused by a small error in some line-of-sight data within the game's WAD file.

See also youtu.be/woOXK4jdA2E for another example of this phenomenon.

This is a video conversion of the .lmp file E2M3NOCU at ClassicDOOM.com:
classicdoom.com/odddemos.htm#e2m3nocu

Timestamps:

0:00 - Start (Skill 3)
0:05 - Optional shotgun
0:08 - Removing other enemies
0:11 - Location of 'blind' Demon

This video is part of the ClassicDOOM 'Odd demos' playlist:
youtube.com/playlist?list=PLF11A841BE9DE443E

#doom #odddemos #classicdoom