Tobian's Ultimate Circle

Tobian's ultimate circle is completely invulnerable, yet cannot be used to protect a creature attacking another. To cast the spell, the caster makes a circle of gold dust. While preparing the circle, the caster decides if it protects against the inside or the outside. If the circle faces inward, nothing within can escape or attack through the barrier by any means until the spell expires or the circle is broken from outside. If the circle faces outward, anything inside the circle cannot be harmed by any attack from outside.

In all cases, any force or attack brought to bear against the invulnerable side of Tobian's ultimate circle is reflected back against the initiator of the force. However, if a creature moves or attacks through the protected (non-invulnerable) side, the spell is broken. Thus, a protected creature, completely safe inside the circle, destroys the protection upon leaving or attacking from the sanctuary.

The caster can, by a supreme act of will, open the circle for an instant to allow teleportation or plane shifting-just long enough to trap a creature inside or bring someone through the barrier. This is the only way a creature can pass through the wall without being bounced back or breaking the spell.

The caster can make the circle permanent with a permanency spell, though it can still be broken by someone walking through the opposite side.

The material component is the 10,000 gp of gold dust used to form the initial circle.