When do you write a full set of rules?

When you're ready to. That's a facile answer, but true. The real question is, when should you write a full set of rules? I find the idea of writing complete rules without playing a game breathtaking, because it will be SUCH a waste of precious time. Early in the "history" of a game you need to concentrate on changes, not on things staying the same, but a full set of rules tends to make one more reluctant to change. Moreover, you can waste a lot of time writing rules for something that will be thrown out of the game at first play.

I have designed a great many games now, so my "mind-conception" gets better and better. That is, when I finally decide to play, I'm more likely to find that the game works fairly well at first play than I was a couple years ago. Nonetheless, I have never written a set of rules before first play. At best I have a set of notes, almost always on computer though I may have written them in a notebook originally.

Those notes are in a program called Info Select (somewhat like Microsoft OneNote, but it's been around far longer). I might have a note for combat, one for movement, one for the economy of the game, one for how to win, one for the main purposes of the game, and so on. At some point I decide to put the notes into a rules template, so that I have something that is still too rough for other people to figure out, but which will provide the basis for the full rules. With this version of the rules I have a pretty settled notion of how to play, but no one else could figure it out from the rough rules. In contrast, the initial set of full rules ought to be good enough that someone can play the game from them, though they might misunderstand things and make mistakes.

In the most extreme case, I wrote a full set of rules after three plays of a game--a game that I now think may be the best I've designed. I have just played another new game five times, and I have a nearly-full set of rules. In other cases I may have a game that is years old and has been played several times but still is only in note form, or in rough form.

Once again: I find the idea that you'd write (or even try to write) a full set of rules before playing a game, breathtaking. This is sure to be a big waste of time; moreover, it is likely to make you less willing to change the game when you actually get around to playing it.