DO NOT LOAD THIS PATCH IN VANILLA!

This patch should ONLY be used if your source port doesn't support the
optimized blockmap used in the mainline version of MAP20.

This version of the map avoids most of that optimization, and is thus
NOT VANILLA COMPATIBLE, but will work with ports whose blockmap loading
behavior inherited a Boom engine bug.



You do NOT need to load this patch if you are playing in:
- Vanilla DOOM2.exe
- Chocolate Doom
- Eternity Engine (current version)
- PrBoom(-Plus) with complevel 2, 3 or 4
- Crispy Doom
- Doom Retro
- GZDoom (current version)
- LZDoom
- Odamex
Any of the above will handle the regular version just fine without patching!



You DO need to load this patch in these ports:
- ZDoom 2.8.1
- ZDaemon
- Zandronum
- PrBoom(-Plus) without a vanilla complevel
- other old unsupported ports derived from Boom or ZDoom

If you're not sure, try playing MAP20 from the main wad. If you can
walk through solid walls, you need to either load this patch or update
your source port :)