Sorry for the vague term. I just mean anything that makes it the end user. Using a class feature as an example: The finished product will probably be written in prose, but draft versions be necessary math plus a brief 1 sentence summary. Less painful when you inevitably refactor! :) 1/2

Oh I see what you mean. When I write wargame rules, thats often how it works, or a draw a prototype stat line without rules first to see how something might look then work out how to translate that into something workable.