A Artificial Causality Phenomenon Weapon (模倣事象兵器 Mohō Jishō Heiki, Imitation Phenomenon Weapon), or Artificial Causality Weapon, is a non-magical imitation of the Nox Nyctores created through advanced technology. These devices rely on atomic power rather than seithr to function. The Idea Engine is an improved version of these devices. These weapons create a resonance effect in proximity to a true Nox Nyctores, as the Nox "recognises it as something similar to itself". These were made by Kokonoe after her study of the Deus Machina: Nirvana. Overall, the weapons aren't as powerful as Nox, however.
Iron Tager is known to possess (or be) one of these weapons, while Ex Machina: Minerva is one itself. Lambda -No. 11- possessed a more powerful version of the weapon called the Idea Engine; she gave it to Ragna the Bloodedge as she died. Arakune is also in possession of a weapon as Relius Clover installed it into him; Relius also created the Detonators which use an Artificial Causuality Phenomenon Weapon as their base.