The Law of Multiverse Travel

The multiverse is a vast web of different universes blocked off from each other. To travel between these realms you must break the border using a large amount of dimensional energy. Breaking the border can be risky as it is challenging to put back together safely. If left unchecked the rift created can grow to large and tear a realm apart or allow for creatures of another realm to easily enter unchecked.
Originally only one being was able to traverse realms and because of his unique power, he could easily fix the rifts he created. With the spread of the knowledge more began to travel the realms and gateways would be made to harness and control he rifts.
Though with so many connections being made they eventually grew too much and shattered a realm apart.

Manifestation

Cracks that appear floating in empty space.  Rifts that seem like broken glass separating this realm to another. And dimensional anomalies that can begin to develop causing a blend between one realm and another as it tries to fix its self.

Localization

The most common natural occurring rifts happen around lay points that create more stabilized situations as the conflux of magic in both realms are bumping up against each other. Which realms touch depends heavily without similar the energies are to the different realm in that location.

Type

Metaphysical, Arcane