From publisher blurb:
Combination Characters is a rules add-on for the Transdimensional Adventures RPG system, providing 'dual classing' rules. Whereas with the core rules multiclassing is possible (as an advantage), the more advanced option here allows characters to be built up as combinations of two 'demi-classes' from the list provided, balanced against a standard character but providing expanded options suiting characters with more complicated backgrounds, whether this represents characters who have a secret identity and are heroes by night, who have a current and previous occupation, or who have lived vastly different lives on different worlds.
Includes 20 demi-classes (new or cut-down versions of existing classes): Acolyte, Athlete, Castaway, Demi-Champion, Driver, Expert, Gladiator, Hunter, Lesser Mage, Militia, Mutant Adept, Noble, Outcast, Petty Crook, Sailor, Student/Apprentice, Tainted One, Vigilante (Street Level), Wasteland Wanderer, and Wild Talent.