differing methods of attack, allowing the player to choose the method and sub-region. Generally, the player starts out with a Dungeon Heart and some Imps. The Dungeon Heart has the same purpose as the original game: it serves as the dungeon's life force. If destroyed, the player loses. In Dungeon Keeper 2, the heart has additional functions: regenerating mana (used to cast spells), doubling as a gold-storage area, producing Imps, and sending certain creatures to investigate threats it detects. Gold is the currency used to construct rooms, traps, and doors, and pay minions. Gold is obtained primarily by digging gold and gem seams, the latter providing an unlimited supply. This is performed by the Imps, the main workforce of the dungeon, who dig and claim tiles for the player to control. Another main task Imps perform is the fortification of walls adjacent to tiles owned by the player, although this no longer makes them impenetrable to enemies, but merely makes digging take longer. The primary rooms include the Lair, Hatchery, Training Room, Library, and the Treasury. These have the same purpose as the first game: they function as a resting place, feeding place, training area, research area, and gold storage area respectively. The only major difference is that the Training Room can only train creatures up to experience level four. Further experience can only be gained through real combat, such as fighting in the new Combat Pit, where creatures fight against one another. The higher a creature's experience level, the stronger and more powerful they become. The highest experience level is level ten, and creatures cannot achieve levels nine or ten via the Training Room or Combat Pit. Other rooms include the casino, where creatures gamble for either pleasure or to be exploited for gold, the Workshop, where traps and doors are produced, and the torture chamber, where creatures are tortured which can convert enemy units into friendly units. Traps include the Sentry trap, which shoots nearby enemy creatures, the Fear trap, which scares enemies away, and the Alarm trap, which alerts its owner if it detects enemy creatures nearby. Doors block enemies while still allowing its owner's creatures passage. They come in various forms, such as Wooden, Braced, Secret, and Magic. Secret doors imitate walls, and Magic doors defend themselves by shooting enemy creatures. Bridges connect areas and facilitate transport over water and lava tiles, the latter harming most