Barons of the Stonelands
From time to time, adventurers recover a pretty trinket from some long-lost hoard, only to discover later that the gemstone is a deadly trap left for some poor fool by a gem master long dead. Others find items that grant a benign spell when touched, crumbling to dust with the activation of its magic. These items are the legacy of gem magic, a long-forgotten art that has only recently been revived in parts of Faerûn.
Gem magic, like rune magic, is the practice of affixing spells to items so they can be triggered later. While it results in the destruction of the gem, gem magic is versatile and faster than other sorts of magic item creation.
A practitioner of gem magic — that is, a character with the Attune Gem feat, — can cast a spell into a gem and set the conditions for its release: time, touch, or proximity of a creature or object described by observable physical characteristics. The gem cannot be set to trigger base don class, Hit Dice, or level, but could be set to trigger on touch or proximity to a creature of a particular type, race, alignment, or appearance.
Placing a spell in a gem requires the caster to prepare the spell he wishes to embed, supply a gemstone worth at least 50 sp per spell level to be used, and spend 1 hour plus the spell’s normal casting time to finish the process.
The character attuning the gem can set the caster level anywhere between the minimum necessary to cast the spell and his own level. A gem can only be attuned with a single spell. The magic gem has a base price of 50 sp per spell level times the caster level (a 0-level spell counts as 1/2 level). You must spend 1/25 of its base price in XP and use up raw materials costing half the base price. The magic gem’s market value equals its base price plus the gem’s inherent value as a gem.
Any decisions the caster would make during the casting of the spell must be made when the gem is attuned. The release of the spell destroys the gem. The act of attuning a gem does not physically alter the gem in any mundane way, although it radiates magic. Recognizing that a gem has been attuned requires a Knowledge (arcana) check (DC 25).
When a gem is attuned, the spellcaster determines its triggering conditions. A gem can be triggered by touch, by an increment of time (such as 24 hours after the gem is attuned), or when a creature of the appropriate type comes within 5 feet of it. The creator determines if the spell’s target is the creature or the gem itself. A chronological trigger always targets the gem with its spell. If the gem’s spell only affects objects, then an object must somehow trigger the spell (or the gem must have a chronological trigger).
If the gem is the target and it is affixed to an object (such as a weapon, door, or other object Medium-size or smaller) or worn against the skin of a creature, the spell affects the entire object or creature. For example, a gem attuned with a protection form evil spell could be mounted on the pommel of a sword or worn on a chain around the neck of a child. If the spell was triggered (such as by the proximity of an evil outsider), it would affect the sword or the child, providing protection against that outsider. While the gem is destroyed normally in this manner, the object or creature is not otherwise harmed.
The gem’s creator may touch the gem safely without triggering it, or deliberately trigger it if he so desires (protective spells are often placed in gems for just this purpose). These protective items are often called gem wards. Common gem wards are the protection from evil gem described above, or gems bearing a feather fall, protection form arrows, or stoneskin spell.
Attune Gem [Item Creation]
Prerequisites: Intelligence 13+, Craft(gemcutting) skill 1 rank, arcane spellcaster level 3rd+.
Benefit: You can store an arcane spell in a gem. You must have the spell available to cast (prepared if you must prepare spells; known otherwise) and must provide any material components or foci the the spell requires. Alternately, you must have with you at the time of attunement an arcane scroll containing the spell you wish to attune, and be of sufficient level to cast the spell. If casting the spell would reduce your XP total, you pay the cost upon beginning the attunement in addition to the XP cost for making the attuned gem itself. Likewise, material components are consumed and spells on scrolls exhausted when you begin casting, but foci are not. The caster level of the spell must be sufficient to cast the spell in question, and no higher than your caster level.
A gem can only be attuned with a single spell. The gem must have a minimum value equal to 50 sp per level of the spell being stored. The base price of an attuned gem (not including the gem’s inherent value) is equal to 50 sp per spell level times the caster level. You must spend 1/25 of the base price in XP and use up raw materials costing half this base price. Attunement requires 1 hour plus the spell’s casting time. The magic gem’s market price equals its base price plus its inherent value as a gem.
Excerpts taken from Magic of Faerûn, with slight modifications. © 2001 Wizards of the Coast, Inc. Reproduced without permission. No ownership of material is intended or implied.