This World Item is unique and is one of the hidden items of YGGDRASIL. It can be obtained by gathering and stockpiling vast quantities of certain types of prismatic ores and then by expending a certain amount of them. The guild Ainz Ooal Gown managed to produce a Caloric Stone by accident after they had stored an unspecified amount of the prismatic ore Celestial Uranium.
The Caloric Stone is considered to be a material with various applications. For starters, it is used to create a golem's core. In addition to that, the World Item is said to enhance the likes of weapons or armors too. Similar to Ouroboros and Five Elements Overcoming, it is also one of the items that allows the holder of this World Item to make requests to the game developers.
- This World Item is unique in that it does not exist as a single standard item, but as a vast quantity of valuable ore.
- Ainz Ooal Gown used the Caloric Stone when they learned that they could obtain that expendable-type World Item in the same way as before.
- Ainz believed that the reason why they had managed to attain the Caloric Stone was entirely due to an extraordinary stroke of luck.