Magical Overload

When accessing magical abilities, it is often thought of to keep the amount of energy spent as effectively as possible, however casting too many powerful spells too quickly can have adverse effects. In studied circles, it is known that if you wish to cast multiple spells quickly, you should keep the total level of spells below or equal to 7. When attempting to cast a spell as a reaction, that spell adds 2 less than the actual level of the spell. A spell cannot remove from the total level of spells.
For example, if a wizard intends to cast Misty Step to escape from close range, and then follow up with a more damaging spell such as Synaptic Static, they can do so. Due to Misty Step being of 2nd level and Synaptic Static being of 5th level; 2 + 5 = 7.
Inversely if a druid seeks to cast the spell Grasping Vine, to move an ally outside of an area, to then follow up with a wide-area damaging spell such as Cone of Cold, this would not be preferred, and exceed the concentration of magical energy and manipulation of the weave 4 + 5 = 9.
Doing such a thing can firstly, can cause the magic to miss-fire and not work at all, but may have additional strange effects. Research has been made as to the exact phenomena and effects that can occur, but no definite answer has been found. The general consensus is that the more powerful spells that are used, the more powerful and possibly dangerous the effects.
The only known standard phenomenon is that if two spells of 7th level or above are cast closely, it might cause an Arcane Coil to form in the area.

Localization

The area that can be affected by magical overload always stays centered around the caster that caused the effect to occur but might either affect only the caster itself or areas around it.