Barold's Lucky Coin

A 2 headed gold coin that when flipped, allows the holder to bolster their luck. Whenever you make an attack roll, an ability check, or a saving throw, you can flip the coin to roll an additional d20. You can choose to flip the coin after you roll the die, but before the outcome is determined. You choose which of the d20s is used for the attack roll, ability check, or saving throw. You can also flip the coin when an attack roll is made against you. Roll a d20 and then choose whether the attack uses the attacker's roll or yours. Once this ability is used, it cannot be used again until you finish a short or long rest.