Circle of Power

A circle of power (or spell circle ) is a circle of space marked out by practitioners of magic, which contains energy and forms an area with special properties.

Second and Third Wars
Circles of power are locations that heroes or units in certain missions of Warcraft II and Warcraft III must be returned or delivered to in order to complete the mission objectives. The circles of power's uses in Warcraft III are much more varied than in Warcraft II because of the addition of more complicated trigger commands that could be implemented.

The archlich Kel'Thuzad needed to stand in a circle of power in order to summon Archimonde.

World of Warcraft
Many circles of power can be seen as doodads, but the term itself has slowly fallen out of use. Trollish circles of power are mentioned in Minshina's Skull (quest) and Convocation at Zol'Heb. The arakkoa are also known to have circles of power in some of their communities, like in Veil Lashh and Veil Vekh.

The mage talent Rune of Power, the warlock honor talent Casting Circle and the Shifting Naaru Sliver trinket are also able to conjure circles of power.