The 12-sided double dice are unique die within a die. The interior die is a mini-d12 and the outer die is also a d12. This two dice combination of dodecahedrons allows for interesting options on every roll. Each time the die is rolled the player will get two results, one from the inside die and one from the outside die. These two results can be added together, multiplied by each other and possibly even divided by each other. Each box includes 40 dice.