The dungeon spawn items screen is used to create a list of items that you wish your dungeon spawns to start with to make them harder to beat and to offer incentives for people to fight them.
The available list of items depends on your dungeon mastery skill which means as your skill gets higher you will find you have access to more items you can use.
You may have up to nine items set to spawn in any one room simply
To set an item to spawn simply find it in the list of items click on it then click Add. Items that are set to spawn will show up gold on the spawn items list and will be above non-spawning items so they are easy to access.
Setting up item spawns will prevent standard loot from dropping including trophy items.