There is really too much here to summarize. It's a 150 page guide to technical writing, as in the writing of technical manuals, using a variety of board game rulebooks the author wrote as examples. I am only 15 pages in, but so far I have to say the boardgame approach with all its images makes this a much more fun read then any other guide I have seen for writing manuals. It is just about writing though. I don't think you'd gain much if you are just a general boardgame fan looking for a behind-the-scenes look at rulebook creation (if that is even something people look for??)
Ironically these two comments seem to indicate a guide to technical writing, that did not view technical writing itself as a technology which they were writing about?
Like, should start with a "quick start overview" about here's how the process looks, etc.?