There are Objects found within the scenes on Knights in the Nightmare; causing enough damage to them will make them yield their items. Damaging objects is how key items are obtained. When objects have taken 100% damage, they become fragile, which will then allow for a Warrior's skill (even with minimum charge) to break the item completely. This is necessary for obtaining more elusive key items, as most objects will respawn after a specific amount of turns.
Some enemies, such as Ogres and the optional boss Scoppio, can completely shatter an object, preventing the player from acquiring some key items; it's the player's responsibility to try to prevent this from happening if they care about the item within.
Objects can be broken down into four main categories: obstacle, container, destructible tiles and cannons.
These types of objects are the most common and on average are able to withstand the most abuse from attacks. These objects must be damaged to their fragile state to get the items they contain. Objects like these tend to vary in size, and can easily restrict the movement of certain knights like the Duelist.
These objects generally consist of much more delicate objects such as chests and vases. These objects cannot withstand as much damage as the obstacle ones. Unlike the obstacle kind, container objects can only withstand damage up to 50-99% to be opened up so that their item is revealed. If a container is damaged to its fragile state (100%) before the item is released, the contents can't be obtained; this forces the player to be mindful of the strength of their unit's skills and charge carefully. If this happens, the object needs to be destroyed and respawned before trying to obtain its item again.
Some chests can turn into Mimics when they are hit. Mimics can attack the Wisp and will slowly try to reach a specific escape tile. The Mimic must be killed before it escapes in order to obtain the item that was inside the chest.
Some map tiles (typically bridges) are considered objects too and can be damaged. These types of objects are generally the most difficult to inflict significant damage on. Duelists and Lance Knights can cross over these tiles when they are intact. Like Obstacles, they must be put into the fragile state for them to yield the item they contain. If a warrior smashes a destructible tile, units will no longer be able to cross over them, so be careful before deciding to break them.
A special object only found in the Tiamat domain in late game, Magic Tiles cause a treasure chest to appear when stepped on. Both the enemies and the Wisp's knights can activate these, although monsters have to be immobilized for the player to make use of it.
If damaged to a Fragile condition, the tiles cease to work.