In Boss Monster there are four Treasure Types: Cleric (represented by a holy relic), Fighter (represented by a sword), Mage (represented by a magical tome), and Thief (represented by a bag of money). The treasure type and amount of treasures present in a dungeon would affects the type of heroes that are lured into a player's Dungeon.
Most Hero cards have a Treasure icon that signifies the type of treasure that they are attracted to. During the Bait Phase each Hero will go to the Dungeon with the most Treasure of their type. If two or more Dungeons have an equal amount of the same Treasure that Hero stays in Town until the tie is broken.
Both Boss and Room cards contains treasures, the type of Treasure that is contained is marked by symbols on the bottom right side of the Boss and Room cards. Most cards contain only one treasure of a certain type but there are some that may have more than one treasure or of more than 1 type. The amount of Treasure of each type a Dungeon contain is represented by the amounts of each symbol it has between the 5 possible Room cards and the 1 Boss card.
There only being 4 Treasure Types is one of the main reasons the game is not recommended for more than 4 players. As some players would be unable to 'corner a market' with over 4.
It has been rumored that Crash Landing, the standalone expansion, may feature all new Treasure Types with sci-fi themes. This might allow the game to be up to 8 player when playing with both Crash Landing and the Base Set.