Prime Arcanum

The Prime Arcanum is located in the center of the House of Rituals is the magic circle where acolytes are tested to become ritualists and earn their ritualist's mantle, through summoning an elder spirit of Maldraxxus through the Grimoire of Ancient Summoning. It is where the house conducts their most potent rituals, used by Kel'Thuzad to even breach the Maw. The Keeper of the Circle is the lich Ton'hamil.

• The Prime Arcanum is likely a reference to the, which is referred to as the arcanum during the Renaissance, here represented as a which alchemic formulas took the form of historically.