Rules, rulings, and role-playing

Once upon a time, about a quarter of a century ago, I played a pen & paper roleplaying game called Ars Magica. Quite an interesting system, as the players were all playing wizards who had to invent their spells on the spot. There was no given list of spells, the player said what he wanted the spell to do, and there were some guidelines on how to determine probability of success. Instead of rules that were binding to both players and DM, there was roleplaying from the players, and spontaneou

World of Warkraft...