Mana

Mana (MP, mana points) is a resource in TERA and in MMORPGs in general, that allows casting some skills. When mana drops to zero, the character cannot perform any spells or attacks. Mana regenerates over time, and can also be regenerated through potions and other items. Mana regenerating charms and some other buffs are merged to Prime Battle Solution which gives increased mana generation for 30 minutes and you should always use in combat.

Certain classes have skills to reload mana. Sorcerer and healer classes, Priest and Mystic have Mana Infusion to reload their mana. There was two classes that started with 0 mana and only gained it slowly or through skills; Slayer and Berserker. These classes had skills Tenacity and Triumphant Shout to gain more mana. Reaper may use Shadow Lash to reload mana.

Offense classes can use Glistening crystals (rather Dyad Niveot with Glistering and Hardy effects) that have MP Regeneration effect when attacking from rear to keep their mana up while attacking.

Combo Attack skill (level 1 auto-attack from left mouse button) reloads mana on most classes. It may be necessary to use this as part of your rotation especially on lancer.

After Apex skills are learned especially Mystic needs every bit of mana they can gain. It may be necessary to use Brilliant crystals on weapon and even roll rings to mana regeneration. Also some foods give mana regeneration.

Background
Term mana comes from Polynesian culture. It is spiritual energy and power that exists in places, objects and persons. Term was introduced to Europe by Robert Henry Codrington in 1891 in his book The Melanesians: Studies in Their Anthropology and Folk-lore. The book has the first detailed description of mana. Codrington defined it as "a force altogether distinct from physical power, which acts in all kinds of ways for good and evil, and which it is of the greatest advantage to possess or control".

Larry Niven used the term in 1969 in his short story, "Not Long Before the End". In the book the mana was the magical energy used to cast spells.