Reality Wrinkle

A reality wrinkle is the zone of planar disruption surrounding an outsider with the Good or Evil descriptor. The moral purity, in either extreme, of the outsider reacts to the planar fabric of the demiplane and creates a region similar to that of a small domain that moves with the creature. Within the wrinkle, a darklord's power over his or her own domain is usurped, including the ability to close the domain's border. A darklords is aware immediately of such a disruption of his or her domain.

Steve Miller

"And for what it's worth, if I had it to do over again, the reality wrinkles would either be smaller or they would be more clearly spelled out. As Ropie said, they weren't intended to be some sort of cheezy safe zone. And those who said they give way [to the approach of a darklord] were absolutely right. They have to." -Steve Miller