Second, it is assumed that while faster than light starships produce prodigious amounts of energy just for the needs of propulsion, there is not enough energy available to perform every possible function simultaneously. Therefore, each ship has to fill out an Energy Allocation form at the beginning of a turn, and 'pay' for all the functions (such as movement, shields and weapons) that it can then use during the turn. This procedure forces players to plan their actions for the following game turn, because systems left unpowered during the Energy Allocation Phase cannot be used during the turn (there is a rule for Reserve Power which a player can use to power up a ship system mid-turn, but this power comes from the ship's batteries which are few).