Caster Levels
Magic item creation has been altered so that they cast their spells at the level of the creator.
Example: A level 6 Wizard casts Ghostly Visage on a scroll. The scroll will be named "Ghostly Visage L6" and when used, the effect will last for 6 turns. The text of the scroll's description will still say "Ghostly Visage (3)", but that is superseded by the Thain-created L6 in the name.
Spells that do not scale with casterlevel (e.g., Remove Curse, True Strike) simply ignore this new caster level scripting and labeling.
Spell Gems
In addition to scrolls, potions and wands, there are enchantable gems on Thain. These can be used by anyone, regardless of class or UMD skill. They can be created by a caster with any of the item creation feats: Scribe Scroll, Brew Potion or Craft Wand.
The highest quality of these gems can hold spells up to the ninth circle, which is their advantage over potions.
Aside from the obviously-named "Attuned Gems", the curious researcher investigating the properties of other gems may find there is more to them than the common person would expect.
Costs
Creation costs are a certain amount of gold, and one tenth that amount of XP. Caster level is the number of ranks in the spell-casting class of the PC for spells which scale in power or duration with the caster's level. For spells which are invariant, the caster level is fixed by Bioware and is the number at the bottom of the item description in parentheses (e.g., Dismissal, which has a spell innate level of 4, doesn't scale in duration or power, and the scroll casts as if the caster were level 7 per Bioware, so that's the value of casterlevel used in the formula below for that spell).
Scrolls: 3 * (spell innate level)^2 * (casterlevel)
Potions: 3 * (spell innate level)^2 * (casterlevel) * 2
Wands, 50 charges: 3 * (spell innate level)^2 * (casterlevel) * 40
Gems: 3 * (spell innate level)^2 * (casterlevel) * 3 / 2
Cost Examples:
A level 20 Wizard scribes a scroll of Tenser's Transformation: 3 * 6^2 * 20 = 2160gp, 216xp
A level 16 Druid brews a potion of Camouflage: 3 * 1^2 * 16 * 2 = 96gp, 10xp
A level 10 Wizard crafts a wand of Polymorph Self: 3 * 4^2 * 10 * 40 = 19200gp, 1920xp
A level 20 Cleric imbues a gem of Gate: 3 * 9^2 * 20 * 3/2 = 7290gp, 729xp
A level 15 Wizard crafts a scroll of Dismissal: 3 * 4^2 * 7 = 336gp, 33xp
Nota Bene
Crafted Items are marked "stolen" so that the disparity between the NWN engine price and the in-game cost of these items can't be exploited to get rich quick.
