Everything costs energy, but nothing takes quite like defiling does. In the world of Athas, a defiler is seen as the vilest plague on the planet. While psionics take the energy created from a strong mind, primal from the forces and spirits of nature, and shadow from the gloom of the Shadowfell, Arcane powers takes from the life force that composes everything. A defiler gains his powers by stealing from others and the very planet, the desert world only an echo of its former self from the use of such.
For this campaign we will use the standard rules for defiling as written on page 80. As such only Arcane classes can innately Defile and only originally on Daily powers.
Defiling will often have strange and unexpected costs when being used, beyond the basic damage to your allies. It is a dark deed, but very powerful and I hope to be able to recreate that feeling as best as I can. Sometimes defiling will have very powerful effects that seems to have few consequences, i.e. the damage to your allies only, and other times the punishment will be difficult to swallow.
But have your fun, it is a tool to use! But be wary as well… Anyone caught defiling in towns or by other innocents will be branded as a defiler, and those that know will be wary and hate you. And they will even send the guards after you!
And, while all magic is inherently damaging, you can instead preserve! This will allow you the ability to disguise you magic as another source, as well as protect those around you. Very few consequences, but also no extra reward. (Defiling can never be hidden, other Arcane users can identify your spell casting as arcane will sufficient arcana check).