Explosive Charge

The Explosive Charge is a type of Oak Item. When equipped, it causes new mining layers in the Underground to start with damaged tiles. Any tiles it affects have a single layer removed. Unlike most other Oak Items, it is not unlocked by capturing unique Pokémon and instead can be bought from the Cinnabar Island shop in Kanto.

Details
For this Oak Item, skipping layers in the Underground counts as gaining progress toward the next level.