Retention is a system you run, not a document you finish. As the plays get sharper in the field, the refinements land here first. Ask questions, tell me what happened when you ran a play, and stay current between editions.
Everything that has sharpened since the book shipped. Each entry is tagged to the chapter it touches, newest first.
Two ways in. Ask a question and I'll reply by email, the best ones answered publicly above. Or report how a play landed in the field, that is the raw material for the next edition.