Schema

Schema are engraved plaques, often made from carved wood or metal inlay, that appear very similar to a scroll. The truth of the matter is that they are very much like scrolls in that each schema holds a single spell that can be cast as a spell activation item with a standard action that provokes. The necessary checks, and possibility of mishap, for scrolls apply to schema as well. Where they differ is that schema are not used up when the spell is cast. A schema can provide the necessary energy for a single casting of the spell inscribed on it once per day and no mishap can accidentally destroy a schema. In all other ways, a schema acts a scroll.

Creating a schema requires both the Scribe Scroll and Craft Wondrous Item feats. The base cost of a schema is equal to Spell Level x Caster Level x 400 gp. If the spell to be inscribed has an expensive material cost, that material cost must be paid 50 times as part of the creation. The only spell requirement is the spell to be inscribed. The base cost for schemas, not including the cost of any expensive material component, are listed below.

*Not including 50 times the cost of any material components.

Source: MoE, pg. 122