Inspiration

Once within the next 10 minutes, the creature can roll the die and add the number rolled to one ability check, attack roll, or saving throw it makes. The creature can wait until after it rolls the d20 before deciding to use the Inspiration die, but must decide before the DM says whether the roll succeeds or fails. Once the Inspiration die is rolled, it is lost. A creature can have only one Inspiration die at a time. You can use this feature once a long rest.   Your Inspiration die changes when you reach certain levels in this class. The die becomes a d8 at 10th level, a d10 at 12th level, and a d12 at 15th level.