The item covers the system that was first created by Clinton R. Nixon for The Shadow of Yesterday
and later revised and clarified by Eero Tuovinen in Solar System
. It makes use of Fudge dice, and some of its unique features include
- Keys - players earn experience points by acting in concordance with, or against, motivations, convictions, cultural constraints or similar elements (called Keys).
- Secrets - powers, skills, traits and other abilities that characters can use
Lady Blackbird uses Keys and Secrets, although it uses normal dice, not Fudge, and has enough other changes that it can truly be considered a separate system.