Talismans gives you a +50% coin bonus on winning. You spend one every time you win a duel. It takes 60 minutes to refill one Talisman. Maximum of three Talismans may be refilled.
You can see how many Talismans you have and how much time you have left until one is refilled by pressing "+" sign near Talisman. You can also use Gems to refill Talismans, ask your friends for them or watch a Video and get one free.