Magicka

Magicka is one the three basic character attributes, the other two being Health and Stamina. It is represented by a blue bar and governs the energy that is used to cast all spells. The base amount of magicka is determined by intelligence level and race (some races like High Elves and Bretons gain extra magicka).

Magicka can also be increased with items of apparel. For a complete list, see Fortify Magicka.

Casting spells
The amount of Magicka necessary to cast spells is decreased by items like:
 * Diadem of the Savant

Potions

 * Potion of Minor Magicka
 * Potion of Magicka
 * Potion of Plentiful Magicka
 * Potion of Vigorous Magicka
 * Potion of Extreme Magicka
 * Potion of Ultimate Magicka
 * Potion of Ultimate Well-being