Jaggar's Strengthened Bastion

Prince Jaggar designed his strengthened bastion spell to fortify his castle in wartime. It makes one or more inanimate objects resistant to magic, giving them a saving throw against spells that normally allow none. This spell also proves effective when cast on portions of a wall, a door, or similar area. For example, Jaggar's strengthened bastion allows a saving throw vs. knock, dig, avoidance, distance distortion, passwall, transmute rock to mud, glassee, move earth, stone to flesh, vanish, glassteel, crystalbrittle, and other spells that affect objects. The objects make a saving throw vs. spell at the level of the caster of the fortifying spell. This spell can be combined with the permanency spell.

The material component is a piece of chalk the wizard uses to inscribe a small magical symbol on the affected object. The marking immediately disappears, visible only via true sight, a gem of seeing, or similar magic.