In a comment to Grognardia’s post, “Ability Checks”, Rach wrote: “At what point then does D&D end and Cowboys and Indians begin?”
For me, it’s when all the participants choose one person to be the judge in order to resolve conflicts. Yes, it means that you have to trust that person. Yes, it means that they may make mistakes. But in exchange you get a game of infinite scope. Everything else is embellishment.