Magic Circuit (魔術回路 Majutsu Kairo) is a network of circuitry installed inside any object which is used by a mage as a substitute for rituals to cast faster, stronger and more complicated magic arts by transmitting magic energy into it. According to the Magic Activity Dissonance Theory, only a particular type of magic circuit is allowed to be installed inside an object; though, with the exemption of the magic circuit, Eve’s Heart. All automata are installed with the magic circuit, Eve’s Heart, and almost all of them are installed with another different type of magic circuit along with it.
Background[]
In 1500, Rube Goldberg established the basic theory for the magic circuit. In 1723, from being custom-made, it began to be mass produced.