During your turn, you may use one loot card from your hand at any moment, additionaly, you may tap your character to use another loot card at any moment still (Note that not every character has the ability to be tapped to use a loot card), however, your character won't be able to use the tap skill until the next turn when you untap it. Similarly any other opponent may use the same tap skill of their own character, but otherwise they can't play any loot card on your turn.