Materials: A pencil, a 3”x5” notecard, two coins, some poor fool to be your Game Moderator, already knowing what a “RPG” is. Characters: Write out a description on the notecard. Make it cool but not stupid. If the the GM doesn't like or can’t read it, erase everything, start over. Adventures: Read good books, watch cool movies, riff away on your own version. Actions: When something is in doubt, toss a coin, heads you succeed, tails you fail. If things are in your favor, flip two coins and succeed if either lands heads. If you’re disadvantaged, flip two coins and fail if either lands tails. GM and player hash out what failing, succeeding, advantaged and disadvantaged actually means. What’s written on your card matters. Damage: If you get walloped, flip your card over; you can’t use any of the stuff written on it until you’re fixed. If another really bad thing happens before you’re fixed, game over. Advancement: Mark your card’s corner when the GM agrees you’ve achieved something especially awesome. After you’ve marked all four corners, get a fresh card, rewrite your character, but a little more amazing now.
“Cast-a-Quadrans” is a semi-satirical culmination to a discussion I’ve been pursuing for a while, particularly with fans of super-heavy physics-simulator traditional rules-systems like Hero, GURPS and Rolemaster. More or less, given the difficulties of scheduling and the rarity of free time, combined with the casual effort most players are able or willing to put towards rules study, little of those systems ever actually makes it to the game table. In 95% of actual play, 95% of the official rules will never be used, and what actually gets used is GM/Player negotiation moderated by oracular dice rolling. When that’s the case, you might as well just flip coins. Most groups I’ve witnessed allegedly playing a expansive rules system are, upon observation, pretty much really playing “Cast-a-Quadrans” already.