Treasures are looted from treasure tiles. In order to avoid spoilers, the treasure tile, once looted, results in a treasure number. Consulting the treasure annex will reveal the treasure's content.
While a majority of treasures have positive outcomes, some of them can result in damage or negative conditions (representing the traps or creatures that can linger into chests).
What is looted is automatically added to the character's inventory. It cannot be traded. For more details, see Inventory. If a character already has the item in his possession, a duplicate is impossible and the item is immediately sold.