Dan & Paul discuss experiences in TRPGs when players don't know the rules. Is it fundamentally fair or unfair? Does it add to the immersion of the roleplay? What added flexibility dos it give to the GM? Is exploring the rules of a new world an essential part of roleplaying games, that we've lost along the way?

Games with concealed rules are games where the rules are intentionally concealed from new players, either because their discovery is part of the game itself, or because the game is a hoax and the rules do not exist. In fiction, the counterpart of the first category are games that supposedly do have a rule set, but that rule set is not disclosed.

For example: Paranoia is a tabletop role-playing game in which the rules are considered "classified". Only the Gamemaster has full knowledge of the rules, while other players must deduce them by trial and error as they proceed through the game. The game acknowledges that players may read the gamemaster section, but demonstrating knowledge of the rules is considered treasonous, and the gamemaster may also make arbitrary changes.

This description uses material from the Wikipedia article "List of games with concealed rules", which is released under the Creative Commons Attribution-Share-Alike License 3.0.