Mana is a resource required for charging spells and training followers. The more mana available, the faster these tasks are accomplished.

Mana charges automatically based on the activity level of your followers.

 

Braves who are either in a hut or active in any other way give much more mana than idle braves; however, a brave gives theexact same amount of mana whether he’s active or in a hut.

Braves in small huts give the same mana as in medium or large huts - what matters is that idle braves give less mana while braves doing something or being inside a building (working braves) grant way more mana.

Troops give much less mana than braves. Active troops give more mana than inactive troops.