Mutants and Masterminds RPG The Expanse Game Master’s KitThe Expanse RPG brings the universe of James S. A Corey's sci fi novels to the tabletop. Being a GM for such a rich setting is a big job, so The Expanse Game Master's Kit is here to help. Being a GM for such a rich setting is a big job, so The Expanse Game Master's Kit is here to help. It also includes 4 quick reference cards that put the stunts and actions at your fingertips, a combat tracker that you can write on with wet or dry erase markers, a set