Adriana, I would think that it would really be up to each individual & couple as to what "the rules" should be. I can't imagine there would be any limit to the # of rules as long as everyone was in agreement to them. The most important rule, however, is that everyone involved be treated with respect. If you are in agreement to accepting a Master, so be it ... or humiliated and commanded to do to do things you normally wouldn't do. Its really up to what everyone is in agreement to, don't you think? This stuff isn't for me, but some here feel "empowered" by it ... different strokes for different folks!