If only the front side of a door needs a key and the door can also be opened from the back side without a key, a monster can sometimes open the door from the locked side.
- All monsters can do this, but only Arch-Viles, Arachnotrons,Cyberdemons, Demons, Spectres and Revenants can open doors thicker than 7 units. This is because they are faster than the other monsters (the faster a monster is, the thicker partly locked doors it can open).
- Doors which are only locked from one side are rarely used by map authors, which is why the bug can only rarely be witnessed.
- The only instance of this type of door in the commercial IWADs is the red key door in Doom II MAP27.
Credits and acknowledgements[]
- The great moderator at Doom Wiki for letting me use this info. Thanks! :)