The Elemental Barrier

In the first Era of Ethelas the barrier between the Elemental Plans was porous. Wizard drew from the Elemental Planes and bargains were widely made with Elemental Powers.  Somehow, something or someone brought Ethelas into the Multiverse. For Ethelians it was unknown how or way the Gods came into the world. But they did. In truth a barrier was lifted from the world, bringing it out from this Elemental Wrath and connected it with the Outer Planes.
Wizards and those who study the Planes know the Elemental Barrier was empowerd and stabilized. 
The Elemental Barrier is the magical separation between the Elemental Planes and the Material Plane (this World). It is tought that this is the greatest gifts the Pantheon of Gods brought. 
There are many places in the world where once the Elemental Barrier was porous and still is weaker there than at other places. These nodes of Primal Elemental Powers are well guarded in the Civilized World. In the Wilds these spots are known and unknown for their potential.