A Perimeter License reduces the number of reinforcements in Shadow Dungeons. * Decreases the chance of enemy reinforcements joining battle. * Can only be activated when your Main Character is not in battle. * If a player is already using an Perimeter License, the existing license's expiration date will be extended for the duration of the new license (it does not start over at 0). * Check the Buffs window for remaining days and time on this license.