Mana is the magical energy that serves as ammunition in Hexen. It comes in two forms, Blue Mana and Green Mana. The first weapon of each class consumes no mana, the second uses blue mana, the third is powered by green mana, and the fourth requires both varieties. In addition to containers of blue and green mana, there is also a Combined Mana container that provides both types in one package.

The player can store 200 mana of each type regardless of class.