Talk:MAP18: The Courtyard (Doom II)

Bug #1: Sector 15 is a hidden aperture, with ceiling and floor heights set to 144 (the floor later drops to 16). Bordering it on the sides are two linedefs (451 and 459) that are set as two sided. The front sidedefs of both linedefs are part of sector 15, but the back sidedefs are each defining unique sectors (16 and 38) which are set to floor heights of 0 and ceiling heights of 192. As these sectors only have one sidedef each and no associated middle texture, they open to the outside map. One provides a view of an adjacent room, while the other provides a hall of mirrors shimmering effect.

Ummm - source?