Mana is the magical energy used in the game Total Annihilation Kingdoms. It is the only resource used for building structures and producing units.
There are two types of mana. The player's mana supply and the unit's personal magic supply.
The player's mana supply is actually the financial resource of a fraction, much like the "metal" and "energy" resources of the original TA, and it is used to "build" or repair units and buildings. When a builder of any faction is creating something, the amount of mana needed for its construction is drained over time until it is completed. The same goes for a unit being produced in a factory. By using multiple builders at once for a single building's construction is going to impressively speed up the building progress, but the player's mana will be drained much faster over time as well. The monarch can also be used to speed up the construction. Different builders can only help speed up production of things they can normally build. The monarch can speed up what is produced by any builders on their team, as well as in factories.
A player's mana supply is represented by a purple/blue liquid inside a glass sphere in the right-bottom corner of the screen. The positive (+) number to the left of the glass sphere represents the amount of mana gained per second, while the negative (-) number to the right represents the mana drained during the same time period. There is also a number above the sphere which shows the amount of the total mana the player can store. It is commonly known that Lodestones, Divine Lodestones, Monarchs, the various training facilities and the various builders a player controls both add to the mana gained per second and to the total mana supply that can be stored. However, Lodestones and Divine Lodestones add by far more mana than Monarchs, training facilities and builders do.
The magic supply is the personal mana supply some units have, like the four monarchs of Darien (five with the expansion pack). This supply is depleted when they perform some special attack of theirs, usually magical in nature. The amount of personal mana drained varies from unit to unit and it is also relative with the type of attack the unit performed. Fortunately, a unit's mana supply always recharges in a slow pace by its own and it is not related with the player's mana supply in any way.
Though Total Annihilation: Kingdoms has just a single unlimited resource (mana) the wise management of it is crucial for the player's success. Careless players may find their mana supply drained quite easily during a skirmish or an online game which will almost halt all their unit/building productions, making them easy prey for their more experienced opponents.