When an ESP spell is used, the caster is able to detect the surface thoughts of any creatures in range — except creatures with no mind {as we know it), such as all of the undead. The ESP is stopped by 2 or more feet of rock, 2 or more inches of any metal other than lead, or a thin sheet of lead foil. The magic-user employing the spell is able to probe the surface thoughts of 1 creature per turn, getting simple instinctual thoughts from lower order creatures. Probes can continue on the same creature from round to round. The caster can use the spell to help determine if some creature lurks behind a door, for example, but the ESP will not always reveal what sort of creature it is. The material component of this spell is a copper piece.