Craft Contingent Spell( Unapproachable East, p. 42)
You know how to create contingent spells, which are semipermanent spells that can be "worn" and activate under certain conditions.
Spellcaster Level 11,
You can make contingent any spell for which you meet the prerequisites. Crafting a contingent spell takes one day for each 1,000 gp in its base price. To craft a contingent spell, you must spend 1/25 of its base price in XP and use up raw materials costing half its base price. Some contingent spells incur extra costs in material components or XP as noted in their descriptions. These costs are in addition to those derived from the contingent spell's base price. See Contingent Spells in Chapter 4: Magic and Spells for more information.