The DooM Game Editor book + CD-ROM is a good place to start learning how if you've never done it before. The CD-ROM includes software for editing wads.
Single-patch List - If you use tricks of the DooM engine in your level designs, you might find that you need to know which textures are multi-patch and which are single. Some tricks take advantage of middle textures on 2-sided line defs; multi-patch textures will give HOM if used that way. It's handy to have a list of all the factory single-patch textures in Doom II for quick reference.
As I play, I sometimes get ideas about how to make better DooM WADs. Sometimes they come to me kind of out of the blue, sometimes I collect them from what others have done well. My Thoughts On Wad Design is a running collection of these random ideas, and may be updated from time to time (last update 29 Jan 2002). You may view it online or download it as zipped plain text (2k).
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