2017 · Sourcebook (rules/options to enhance play)

Celestial Mechanics

A rules supplement for d20-based roleplaying games that adds narrative control without changing existing character creation, combat, magic, or other rules. For actions not covered by the core system, players choose a bid die from d4 to d12 to set the potential benefits and complications, then roll a d20 with the relevant modifiers. Results of 11 or higher succeed, while 10 or lower fail. Even totals let the acting player describe the outcome; odd totals give that control to the gamemaster. Successful and failed actions are tracked with complications, reducing the gamemaster’s narrative workload.