Dungeon tile

A dungeon tile represents one usable space in a player's dungeon. The number of tiles a user is permitted in each dungeon is determined by a number of factors, but the minimum number of tiles for a dungeon is 100.

Starting amount of tiles
Different dungeons have a different number of starting tiles. Most dungeons start with whatever is necessary to connect your Vault to the entrance(s), plus 100 unused tiles. Confirmed exceptions include the starter dungeons (which have an extra 2 tiles to connect the Gold node to the Vault) and the eastern 3-entrance square dungeon, just to the right of the Heart of the Mountain (which starts with only 99 unused tiles, but has the same total amount of tiles as the western 3-entrance square).

How to obtain additional dungeon tiles

 * Research Lesser Stone Binding to receive +25 additional tiles to all your dungeons
 * Research Stone Binding to receive +50 additional tiles to all your dungeons
 * Research Greater Stone Binding to receive +50 additional tiles to all your dungeons
 * Research Forgotten Lore: Dungeon Mastery to receive +5 additional tiles to all your dungeons
 * Buy the Extra Room Tiles pack in the shop (using real money) for +25 additional tiles to one of your dungeons. You can't buy this more than once for the same dungeon, but you can buy one for each one of your dungeons.