Magic Flow

Magic flow is the natural creation of magical energy by the plane itself. Almost every plane has magic flow, though some have more than others. Magic flow is what allows spellcasters to regain their abilities, and it's also what allows sapient races to attune to and create magical items. When not in a location with magic flow, a spellcaster is unable to regain their spell slots, though they can use any spell slots they entered the area with. Items with charges will also be unable to charge in an area without magic flow, and items requiring attunement are unable to be attuned to while in such an area (though they can still be unattuned to normally).
There is, however, a way around magic flow. Since almost everything on a plane creates magic flow, it's possible to harness some of this magic flow into objects or creatures. While most ways of doing this are considered heavily immoral and sometimes outright forbidden, certain ways, such as using the petals of a Crystal Rose, are commonly used by mages of all sorts.

Manifestation

While magic flow itself does not manifest visually outside of creatures who are able to see magic, it can cause many effects that are visible, such as Free Magic.

Localization

Magic flow exists in every location, outside of Null Magic zones.