Game Theory and the VT Shootings

A one-round, two player game:

Let's say you and I have the option to carry. Either we both carry, one of us carries, or neither of us carries.

The Nash equilibrium in this case is that we both carry, because when one of us carries and the other doesn't, the one that doesn't feels unsafe. Independently picking our strategies, we both decide to carry.

Unfortunate effects of restricted-carry areas:
We end up in an unstable situation when we're prevented from carrying because the people that wish us ill will always find a way to carry a gun.

The same situation follows when no one is allowed to carry guns--law abiding citizens do not carry and criminals do not care, leaving good citizens at a serious threat.