While this spell is in effect, the wizard can alter the flight of a single missile that passes within the range of the spell, stopping it or causing it to be hurled back toward its original sender. Missiles returned to sender strike with the sender's THAC0 with a +4 to hit and inflict normal damage. The wizard can affect only a single missile per round. The missile can weigh no more than the wizard's experience level in pounds.
Enchanted items (such as an arrow +1) are granted a saving throw vs. spell to overcome the missile mastery. The saving throw for these items is equal to that of the person who launched them, plus any bonuses of the weapon (+1, +2, etc.). Magic missiles are negated entirely, but only one particular missile of a spread is dispelled in a single round.
The mage does not need to concentrate to maintain the missile mastery and can move and fight when it is in operation. Casting any other spell negates the remainder of the missile mastery spell.
Notes: Rare in the Forgotten Realms setting. Known to be in The Shadowtome.