If you're doing it right, one of the hardest parts of game design is writing clear rules. How to do it varies with your audience. Polish rules as you playtest. Includes Do's and Don'ts handout.
Wargames model the most intricate, complex, insane human endeavor. Topics include modeling, realism and the chaotic nature of history, research, and making sure it's a game not a straightjacket.
Specific problems involved in designing multi-sided (more than two sides) games. Games where you can gain an advantage by talking with other players, and are likely at a disadvantage if you refuse.