Sign of Sealing, Greater

(Spell Compendium, page 190, DnD 3.5)

Abjuration

Level: ; Sorcerer/Wizard 6
Components: V, S, M
Casting Time: 10 minutes
Range: Close (25 ft. + 5 ft./2 levels)
Target: One door, chest, or other opening or open space up to 30 sq. ft./level
Duration: Permanent
Saving Throw: Reflex half; see text
Spell Resistance: No

This spell functions like sign of sealing, except that it can also be used to seal an open space (such as a corridor or an archway), creating a magical barrier of force that repels any creature attempting to pass. In addition, doors and objects protected by a greater sign of sealing are strengthened, increasing their hardness by 10 and granting them an extra 5 hit points per caster level. Any object protected by a greater sign of sealing is treated as a magic item for the purpose of making saving throws and gains a +4 resistance bonus on saving throws. If its seal is broken, a greater sign of sealing deals 1d6 points of damage per caster level (maximum 20d6) in a 40-foot radius (Reflex half).

A greater sign of sealing cannot be passed with a knock spell, but it can be dispelled (DC 15 + the caster level of the sign's creator). It can be disarmed with a DC 31 Disable Device check.

Material Component: A crushed emerald worth at least 500 gp.