Spell Research
September 2006
This page provides expanded rules and information regarding the cost of magical research for new spells. I collected information from various sources, included the DMG, Dragon Magazine, and my own invention, to assemble these rules.
Spell Research
The research of new spells requires the use of a library of magical knowledge. The types and levels of spells that can be researched depend upon the depth and breadth of the library, as indicated by value. The more valuable the library, the higher the level of spells that can be researched. The minimum value of the library required for research at each level is given in Table A3.
Table #A3 — Library Minimum Values
| Level | Value (GP) |
|---|---|
| 1 | 2,000 |
| 2 | 6,000 |
| 3 | 12,000 |
| 4 | 20,000 |
| 5 | 30,000 |
| 6 | 42,000 |
| 7 | 56,000 |
| 8 | 72,000 |
| 9 | 90,000 |
The cost of research with a proper library is 200 gp per spell level per week, plus an additional 100-400 gp per week for incidental expenses. If the character does not have such a library then space must be rented in another’s library. This will typically cost 50-200 gp per spell level per week.
Research helps to build a library. Some materials must be bought and new things can be learned, so that books and papers can be written. 10% of the cost of research goes towards adding to a character’s library. Please note that the character must have a secure space to store such materials, and that may incur an additional cost after the research is completed.
The time to research spells varies. It always takes a minimum of 1 week per spell level, plus 1 week. Each week upon reaching the minimum time the researcher has a percentage chance of success. The percentage chance of success is 10% plus the level of the researcher plus the intelligence of the researcher, minus twice the level of the spell. This percentage is checked weekly until success is reached or the researcher gives up.
For example: Karl Klutz, 10 level cleric with 12 wisdom, decides to research a 5th level spell. His chance of successfully completing the research in the 11th week is the base success value (10) + his level (10) + his wisdom (12) – twice the level of the spell (5*2=10), e.g.,
10 + 10 + 12 – 10 = 22%
So each week he checks for success. Each week he fails increases the cost of his research.
However, if the library is valued above the minimum necessary for research of a given spell level, a maximum of 20% increase in the success rate may be achieved. This bonus is calculated by dividing the value of the library by the minimum value necessary for research. For each whole multiple the researcher receives an additional 5% chance.
The minimum value of the library to research a 5th level spell is 30,000 gp. If the library Karl uses is valued at 75,000 gp, divide the actual value by minimum value, e.g.,
75,000 / 30,000 = 2.5
This value rounds down to 2 and is then multiplied by 5%, means that Karl has an additional 10% chance of success each week.