Creating a new spell and discovering a formula for a potion or magic item takes research. . For a potion recipe or level 1-3 spell, access to a Basic Library or guild is necessary. For a permanent item formula or level 4-6 spell an intermediate library or guild is necessary. For a level 7-9 spell an advanced library or guild is necessary.
To create a new spell, research takes 1 week and 2000gp per spell level. Then there is a flat 20% chance that the research is successful, otherwise time and money is wasted To discover the formula for a potion requires either a sample of the potion and 1 week of work, or work and time equal to a 3rd level spell.
To create a permanent magic item, he must first have a formula, which can be discovered through research in an intermediate or advanced library (magic-users) or meditation and prayer (clerics) or workshop practice (dwarves). After one month’s study or prayer, roll the character’s Intelligence or Wisdom (arcane or divine respectively) or less on d100 to achieve the formula, a re-roll is allowed after each additional week of work. Once such a formula is discovered, it can be used to make multiple examples. Magic-Users can only have a number of permanent item formulae in their spell book equal to their maximum number of spells per level.