- Game Guide(src)
Arcane Power is a resource used by the Wizard in Diablo III. It regenerates fairly quickly, which can be augmented by some Skills and effects. Wizard primary skills, called "Signature Spells", do not cost Arcane Power, but many do not generate any either.
In-game[]
Arcane Power is normally limited to 100, with Wizard-specific items being able to increase its maximum by up to +45 (+54 with Legendary items), plus additional up to +20 from Astral Presence and -20 from Energy Armor (can be +20 as well with Energy Tap rune). Paragon levels may grant +25 more Arcane Power.
It regenerates naturally at 10 per second rate, can be potentially increased by +4.5 from Arcanot, +1.4 from Kormac and +2.5 from Astral Presence skill. In addition, Wizard can have up to 8 (14 with The Oculus) Arcane Power restored per critical hit, multiplied by Proc Coefficient of each particular spell. The Shame of Delsere makes Signature Spells restore 9-12 Arcane Power on cast.
Certain skill runes also recover Arcane Power on hit. Combined with skills like Prodigy, it allows a near-infinite Arcane Power with the proper build and gear. Some Arcane Power-independent builds exist as well.