Magic Limits

Magic, the working of miracles! Well, not exactly. Nanites work miracles every day. But that's not good enough for everyone. For them, there's extra planar power waiting to be grasped at.

The reality of the situation is that Earth's reality is just one layer of a great big sandwich of probabilities and energy states. The sandwich isn't even layered neatly, so a lot of layers are all sprawled on top of one another in contact in different places. Where these layers make contact, energy can flow one way or the other. The physicists were not wrong. Things cannot be created or destroyed, neither can energy, but the world is not a closed system.

Sources

• Most energy flow is natural and constant, creating pockets of 'strange vibes'. Places where things may act a little strangely, enough to draw tourists, but little more.
• Intelligent beings from the other planes can focus and direct the flow of matter and energy more acutely. Not all of them, of course, but we're only interested in the ones that can. Such beings, usually well versed in the mechanics of multi-planar manipulation, gaze upon the earth from where their home touches upon it.
  • Moving planes would take untold amounts of energy and cause massive damage from friction alone. It's safe to assume it just isn't done, at least not by any conscious will.
    • Planes can and do slowly drift on their own.
• Because of this, the contact points are the one thing that most extraplanar creatures cannot control. Their world intersects ours at a specific point, and that's all there is to it, and they have to work with that.