A Rule (権能) is a title belonging to a person that describes their unique otherworldly power.
A Rule is the in-universe term for the supernatural or otherworldly powers one has. The term likely comes from its ability to enact a person’s 'rule' onto reality to overwrite the normal laws of nature,4 similar to how a king can enact his rule upon his people. In exchange for that power however, a Rule must be accompanied by a Role. A Role can alter the way a Rule outputs its own power, changing it to whatever suits the Role best. While Taurus Mask and Shino both share the Rule of Accession, their different Roles produces Rules with vastly different powers as a result. Without a Role, a Rule cannot be used, as seen by Dagon in Raiders of the Lost Isle when he could not use his Rule and was hoping to obtain a Role from Triton in order to obtain his lost power. While one can share the same Rule, one cannot share the same Role-Rule pair in the same world, whether it be Tokyo or Yggdrasil (Fantastic Boyfriends).10
One’s Rule best describes the power one possesses.9 For example, Kengo wields the Rule of Infinitude, which describes how he can gather infinite power within his fists to deliver a devastating attack. Abilities such as these act under a conceptual system; in other words, the specific powers a Rule has can vary as long as it fits within the general ‘idea’ of what their Rule is meant to represent. Akiha Gongen’s Rule of Extinguishing can extinguish both real fires as well as the fires of passion within people, causing his targets to lose their motivation and creative drive. The way a Rule functions can actually be changed, but only if one's Rule originates from the 'enclosed space' within their own body and the majority belief within is somehow changed. Behemoth's Rule was altered because of Inugami entering his body, changing the majority within from a majority of 1 to a 50/50 split. once Inugami left, Behemoth continued to believe that his Rule was changed, and so that became the 'truth' within himself. If Behemoth were to stop believing or find out the truth, his Rule would return to normal.13
Rules are ranked within a world according to a hierarchy which determines which Rules are superior over others and which Rules lose to others.9 In Tokyo, because of the Gates allowing multiple worlds to battle against each other, these mythologies have not had their Rules ranked against each other, causing contradictions between conflicting Rules to take form as Exceptions.
According to Maria, Rules are not inherently good nor bad. The alignment of a Rule is determined by its wielder and how they choose to use their Rule, often influenced by what one's Role dictates them to be.4
Sacred Artifacts act as vessels in which a Rule is housed and used in battle.4 Kengo’s Rule of Infinitude is housed within the Belt of Power wrapped around his hand. Every time he wraps the Belt around his fist, his power increases, storing up power until he releases it all in his attacks. If a Sacred Artifact were to be lost during a fight, one would not be able to use their Rule.
Each Sacred Artifact holds only one Rule. One can own multiple Sacred Artifacts, so it is possible to have multiple Rules; however, each Sacred Artifact can still only house one Rule within itself.
An Exception is created when two contradicting Rules collide, causing the App's processor to freeze and the Rules of the Sacred Artifact to go berserk. If one of the contradicting Rules belonged to a Tokyoite wielding a Sacred Artifact, the Rule will assume the form of the Artifact's original owner. If the Rule belonged to a transient, the Rule will flow directly into their body, overloading their senses and making them act berserk.
In order to resolve an Exception, a hierarchy must be set between the two Rules for the App by establishing which one is dominant over the other. With the Rules having a clear rank between each other, they no longer contradict, and so the Exception disappears along with the Battle Zone.
List of Role-Rule Pairs
Roles/Rules in italics are currently unofficially translated titles.
|Fisher King||???||Abundance (Cauldron/Holy Grail) |
Dragon (post-Ch. 9)
|Rending (Boundless Tail) |
Omnipotence (Ring of Solomon)
Other Indra iterations
|The Hero (Second)||Hero (Discarded)||???|
|Triton||All-Father (Given to Dagon)
|Witch of Orleans||???||Binding|
Examples of Other Roles/Rules
- Rán, Aegir's spouse from the world of Yggdrasil, possessed the Role of the Plunderer. However, she would later give up her body and entrust all her memories into her Sacred Artifact, the vast ocean itself, thus becoming one with the sea. Her Role would live on in Yggdrasil's ocean, becoming a System itself that steals and hoards living memories. The System divided itself into nine devices called the Daughters of the Waves to gather memories from wandering sailors more efficiently and effectively.11
- According to Shinya, the Role of the Sacrifice is for someone who is offered up for the benefit of their home world. He may be alluding to the Three Beasts of Eden, though this is never confirmed.11
- The fae in the world of Tír na nÓg possess the Rule of the Changeling, which allows any injuries they sustain to be transferred onto someone else. The only way to defeat them is to eliminate them instantaneously, such as with Balor's Evil Eye.
- According to Alice, she and Sanat Kumara share the same Rule of Memory Manipulation, though this is unclear if this is meant to be their actual Rule as it does not fit the usual naming convention for Rules.22
- Taishakuten's Rule of Thunder likely applies to all iterations of Indra that exists in other worlds. It is not specified if his Rule of Storms apply to other Indra iterations as well.6 20
Examples of Matching Role-Rule Pairs
- Perun from the world of Kitezh shares the same Role and Rule as Zeus from Olympus, blocking him from entry. Zeus currently uses Shinya as his proxy.10
- In the newly created world of Yggdrasil (Fantastic Boyfriends), Horus had stolen the title and power of Demon King from its rightful owner Nekros because of his similar power to raise the dead. Once Horus was defeated and the Black Core was removed from his body, Horus would lose the title of Demon King, giving Nekros the opportunity to take back his power.10
- The original Daikoku from the Land of Wa shares the same Role and Rule as the Exception Mahakala. If it wasn’t for Okuninushi inhabiting his body, he would have been barred from entering Tokyo.
- Suzuka's Rule of Revelation only applies to one of her three swords. The other two Rules are currently unknown.
- In the Raiders of the Lost Isle event, Triton gives away his Role of the All-Father to Dagon in exchange for the Role of Educator. It's unclear if Triton regains his original Role or keeps his Role of Educator after Dagon's defeat, and what his Role is in other loops.
- The Protagonist is the only character to have their Role change during the progression of the story, going from 'Wanderer' in the beginning of the Main Quest to 'Dragon' at the end of Chapter 9.