Charge itens items that protect by a especific specific element consume 1 charge for each damage you get from the element, lets element. let's use the magma amulet as exemple, if an example. If you walk in fire tiles for every tile you walk it will consume 1 charge, charge if 5 mages are attacking you with 4 wand wands of inferno(fire damage)and 1 wand of cosmic ( energy damage) you will lose 4 charges for every turn of attack, some amulets also have more than 1 protection like stone skin either phsyical physical hits or death damage hits will consume a charge.