Energy
From SpiralKnights
Energy is a highly-efficient power source that is used by the Spiral Knights as well as almost every machine on Cradle.
In game terms, energy is an expendable resource that is used to explore the Clockworks. Most commonly, it can be used to power the elevators that connect the various floors of the Clockworks, but can also be used to power other objects in dungeons, such as vending machines or auto-turrets.