You can create your own character and role cards. To balance them with the ones in the box, each character should start with 15 cards on their Card List, no more than 1 d12 in their skills, and no more than 5 different skill modifiers. The sum of the skill dice should be 42. They should have 15 skill feat checkboxes, 10 card feat checkboxes, 4 power feat checkboxes on their character, and 12 power feat checkboxes on their role. Expanded guidelines can be found at paizo.com/pacg.
You can also make up other card types and even entire scenarios— simply follow the format of the ones in the Core Set, choosing villains and henchmen that are appropriate for the power level of your characters. Be careful when setting rewards; you don’t want to give out too much for success.
We have partnered with DriveThruCards to provide a tool that allows you to easily create your own cards and have them professionally custom-printed. You can even get cards created by other community members. Visit drivethrucards.com/pacg to try it out!