An Upkeep Cost is a set amount of File:Icon Mana.png , File:Icon Gold.png and/or File:Icon Food.png which must be paid at the start of each turn in order to maintain the existence of a permanent spell or unit. Virtually all units in the game incur some kind of Upkeep Cost, and all permanent spells (e.g. Enchantments and Fantastic Creatures) must be maintained with at least File:Icon Mana.png per turn. Town Buildings also require maintenance. Failure to pay the Upkeep Cost of any asset will cause that asset to be "destroyed": units are disbanded, while spells dissipate. In either case, you have lost the asset.