Magic-users and clerics in the Glantri setting use the following rules.
Creating any given magic item requires a magical laboratory wherein to work, a formula for the item, one or more spells to be imbued into the item, and one or more exotic components, such as the eye of a cyclops or a thread from a saint's garment. Formulas may be purchased from other spellcasters, found while adventuring or researched in the same manners as new spells. (Scrolls may be created without a formula; this is an exception to the rule.) The costs for exotic components vary depending on what's available and the DM's whim. These costs may turn out to be prohibitive — unless, of course, you want to go out and scrounge up those components personally, leading to what some might call an 'adventure'.
There are three distinct arts of magic item creation, as follows:
Potions and Scrolls
Simple one-use items like potions and scrolls are created through alchemy. Each batch of magical inks or elixirs takes one month to brew up, with one day off per week to do other things. This includes a great deal of cautious ritual, such as measuring each rune on a scroll with compass and protractor or triple-distilling potion ingredients. The time can be reduced to a single week, but this requires a 3d6 prime attribute check; a failed roll indicates that the magic goes awry, spoiling the resulting item — or worse!
The reagents and other paraphernalia involved typically costs (spell level * 500)gp per item created, not including any surcharge imposed when hiring another magic-user to create the item. Higher-level spellcasters can manufacture such items in batches, producing one item for every three character levels (rounded up).
There is no minimum level to create one-use items.
Wands and Staves
Charged items like wands and staves are created through astrology. Each item takes three months to craft: one month under a mutable constellation to make the item receptive to magic, one month under a cardinal constellation to instill the spell, and one month under a fixed constellation to bind the magic in place, with one day off per week to do other things. This involves carefully associating every step of the process with various astrological phenomena. The time can be reduced to a single month, but this requires a 4d6 prime attribute check; as with single-use items, the result can be anything from a cursed item to an explosion in the lab.
Restoring charges to a charged item requires one week for simple items like wands, or one month for more complex and powerful items like staves. Like item creation, this requires an auspicious astrological conjunction to perform effectively.
The exotic components and other materials required to construct a charged item typically cost (spell level * 5000)gp to create a fully charged device. Recharging the item typically costs (spell level * 100)gp per charge imbued. This requires the appropriate formula. Knowledge of such formulae is rare; a magic-users with the appropriate formula will typically charge (spell level * 250)gp per charge to recharge it for you, though this price will vary.
Crafting a charged item requires an enchanter's dweomercraft or the spiritual resources of a curate (5th level) to create such an item safely. A lesser spellcaster may attempt it, even a lowly seer or adept (2nd level), but this requires a 3d6 attribute check under normal conditions or a 5d6 attribute check if the process is rushed.
Permanent Enchanted Items
Permanent items like swords and armor are created through theurgy. Each item takes nine months to birth, with one day off per week to do other things. The creator spends this time summoning a spirit, bargaining or commanding it to service, and binding it into a specially prepared vessel. The time can be reduced to three months, but this requires a 4d6 prime attribute check; if the roll fails, failure can mean a useless item, a weak or defective item, a cursed item, or unleashing the spirit to act in the world as it pleases.
The exotic components and other materials required to construct a permanent magical item typically cost (sum of all spell levels * 10,000)gp.
A sorcerer or a bishop (7th level) may craft permanent items normally. A mere magician or vicar (4th level) may attempt to do so, but this requires a 3d6 attribute check under normal conditions or a 5d6 attribute check if the process is rushed.