For the vanilla version of the spell, see Mordenkainen's Sword.
Mordenkainen’s Sword
Level: 7
School: Evocation
Range: Personal
Duration: 1 round/level
Casting Time: 7
Area of Effect: Special
Saving Throw: None
Upon casting this spell, the wizard brings into being a shimmering, swordlike plane of force. Once the spell is cast, the sword will float in the air completely under the control of the caster, until the spell duration expires or the sword is dispelled. The sword acts as a +4 weapon in all respects and attacks on its own once each round, inflicting 5d4 damage when it hits a target. It has 100% resistance to almost all forms of dmage (acid, cold, fire, electricity, poison, etc.), and 95% resistance to physical damage, but it’s vulnerable to pure magic damage. The sword is immune to mind affecting spells, has 36 hit points, AC 5, and THAC0 2. Note that this spell does not prevent the caster from performing any other actions while the spell is in effect.