Library

Cost per tile: 200
 Health per tile: 320

Monster Attracts                         Size Needed                Also Needs
 Warlock                                          9 tiles                         None

 The Library is an essential part of your dungeon. Without it you won't be able to build advanced rooms or cast spells. You should make your Library as efficient as possible - make it square, build it away from the more active rooms, and reinforce the walls. Also, if you can, make sure there's only one doorway for this room.
 Under no circumstances should you build a doorway leading to a Treasure Room or a hatchery from your Library. While your researchers may have to walk a bit to eat or get paid, other creatures won't use it as a hallway - a surefire way to annoy your Warlocks, who will eventually open fire on trespassers.
 Warlocks and Dragons will spend most of their time here, but you should take them out for the occasional training session. Warlocks are great ranged fighters at higher levels but terribly weak at lower levels.
 Once your research is complete, don't sell off the Library no matter how tempting it may be. If you sell sections, you'll lose the spells stored there.
 Here is the order of research in the Library. The first few generally already exist when you start a level:

 Research  Type:

1- Create Imp * Spell
2- Treasure Room  * Room
3-Lair * Room
4- Hatchery * Room
5- Training Room * Room
6-Library *  Room
7-Sight of Evil  * Spell
8-Bridge  * Room
9-Speed  Monster * Spell
10-Must obey * Spell
11-Guard Post  * Room
12- Call to Arms  * Spell
13- Workshop * Room
  14 -  Conceal Monster * Spell
  15 -  Barracks  * Room
 16-Hold Audience * Spell
 17- Prison * Room
  18 -  Cave-in * Spell
  19 -  Torture Chamber *  Room
 20- Heal * Spell
 21- Temple  * Room
  22 -  Lightning *  Spell
 23-Graveyard * Room
24- Protect Creature * Spell
25- Scavenger Room *  Room
26- Chicken * Spell
27- Disease * Spell
28-Armageddon * Spell
29-Destroy Walls *  Spell

 Note: Spells and Rooms marked with an asterisk ("*") normally appear when the level starts except during the first few "tutorial" levels.