Barons of the Stonelands
The process for researching a new spell is similar for all spellcasting classes.
First, the player must get approval for the spell from the GM. Usually, this approval will be granted only for a weaker or stronger version of a spell, or for a spell that is normally available to a different class. In the case of wizards, if the spell is on their spell list, approval is automatic.
Once approval is gained, the PC may begin research. Research takes two weeks per spell level, and requires various mystical reagents worth 500 sp per level. These reagents are inks, incenses, herbs, and various other materials that will be used up during the research process. If there is a costly material component required for spell casing, then three samples must be provided per week of research. If there is a focus required, it must be provided at least halfway through the process.
At the end of research, the PC must pass an appropriate knowledge check and a spellcraft check, both with DCs equal to 20 + the spell’s level less one squared . So a 1st level spell requires two DC 20 tests, and a level six spell requires two DC 45 tests (20 + ((6-1)x(6-1))). If both checks are passed, the spell is researched and the PC may add the spell to their list of available spells. Adding the spell to their list costs 50 sp per spell level in inks, sacrifices or some other sundry appropriate to the trappings of the class. Wizards and Sorcerer’s must pass a Knowledge (Arcana) check. Wizards then add the spell to a spellbook. Sorcerer’s add it to their list of known spells. If the sorcerer already knows the maximum number of spells for a given level, they may use a slot for a higher level spell, or replace an existing spell known. Clerics must pass a Knowledge (Religion) check, and Druids a Knowledge (nature) check.
If either test is failed, the PC must research another week (paying all the incumbent costs), at which point both tests are made again, with a cumulative +2 bonus to the check that was failed to reflect what they learned from the failure. If both tests are failed, then two more weeks of research are required, but the character receives only a +1 bonus to each check. These cumulative bonuses are limited by the player’s level, so a 16th level character may have a maximum of +16 in bonuses. At the end of each week of research, both checks must be made (and passed!) again.
A well stocked magical laboratory or specialized herb garden can reduce the base costs of research by 10%. If both are available, the costs are reduced by 15%. The former may need to be restocked after research has been completed.
As an aside, wizards must research new spells at each level. They no longer gain free spells per level after first.