D&D 5E Spell Research Downtime Rules

Bupp · Jun 15, 2017

Here's some spell research downtime rules I put together for my table.
https://jonbupp.wordpress.com/2017/06/14/spell-research-downtime-activity/

Spell Research

A spellcaster of 5th level or higher may use spell research to gain access to spells that he does not have access to from scrolls, spellbooks, or (if a divine spellcaster) his deity. Spell research costs 1,000gp, and takes two weeks of research, per level of the spell. A cantrip takes two weeks and costs 1,000 gp.

The DC to research a spell equals 10 + the level of the spell you are researching. You get to add your spell attack bonus to the roll. The research DC for a cantrip is 10.

Example: Pyro is an 8th level sorcerer researching wall of bones, a 4th level spell. It will take 8 weeks and cost 4,000gp, and has a DC of 14. With his +7 spell attack bonus, he only needs to roll a 7 or better to succeed.

A spellcaster may also use spell research to create a new spell. The spellcaster must describe in detail the kind of spell he wants to create, and the effects it will have. The DM will then determine if the spell can be created, and if so what the spell level will be. The spellcaster must be capable of casting spells of the spell level the potential new spell will be; otherwise he must wait until he attains a high enough level to research and cast the spell.

A spellcaster can only research a spell if he can still learn spells of that level. A cleric or other divine caster can only research a spell with the permission of his deity (DM’s discretion). The deity will usually remove a spell of the same level from the cleric’s spell list in exchange for granting the new spell.

Libraries

To research a spell, a spellcaster must have access to a library. Wizard’s guilds and major temples often will provide their wizards and clerics access to such a library. If a spellcaster wishes to compile his own library, a minimum of 4,000gp must be invested to allow research on 1st level spells. For each subsequent spell level to be researched, another 2,000gp must be invested.

Having an exceptionally large library aids research. For every 10,000 gp of value above the minimum required for the spell, the spellcaster receives a +1 bonus on his magic research roll (up to a maximum +3 bonus).

Every time a wizard successfully researches a spell, 10% of the gold spent for that effect is added to his library value, reflecting the value of books purchased, notes, and annotations made during research.

Authoritative tomes or rare books found as treasure might provide an additional bonus to research specific spells or types of spells.

jaelis · Jun 15, 2017

What happens if a caster with a "known spell" list, like a sorcerer, uses these rules? Would they gain an additional spell known? That seems too powerful. Would they instead swap out a known spell for the new one?

FormerlyHemlock · Jun 15, 2017

I don't know what kind of feedback you're looking for, but... these rules make spell research much cheaper and easier than what I use. E.g. instead of a library costing (2000 gp * (level + 1)), for me it is (level^2)*1000 gp. Instead of a single DC (10 + N) check to research an Nth level spell, I make it N consecutive successful Int (Arcana) checks of DC (10 + N, +/- 4 per level of spell optimization), each check requiring 1 week and N * 100 gp. That makes it relatively simple for players to research new low-level spells, but researching a new 9th level spell would be a big deal and probably couldn't be done with any optimization: you'll never get a 7th or 8th level spell with the power of a 9th level spell, although you could get a 9th level spell that was really only worthy of a 6th or 7th level slot. (Time Stop qualifies as one such.)

Fireball is an example of an optimized 3rd level spell. If a player tried to re-research Fireball, or a variant thereon such as Acidball, I'd tell them it was right between 4th and 5th level in power, and if they want the end result to be 3rd level, it's at 1.5 levels of optimization (so +6 to DC). Total of 4 DC 20 checks needed, 400 gp each, to research Acidball as a 3rd level spell.

Another example: if you want an improved Magic Jar, it would be +2 levels for letting you possess creatures other than a humanoid, and +2 levels for not having to make Charisma checks to avoid death if the host body dies. If you want both, that would be +4 total levels (6+4 = 10th level, impossible), but I'll throw in a -1 level discount if your perceptions are messed up while you're in the jar (can't see your surroundings, can only sense number and rough strength of positive and negative energy life forces within 100'--you'll have to choose your victim randomly from those with equivalently-strong life forces). Net effect: if you want a spell equivalent to AD&D's 5th level Magic Jar spell, you can have it as a 9th level spell.

jaelis said:
What happens if a caster with a "known spell" list, like a sorcerer, uses these rules? Would they gain an additional spell known? That seems too powerful. Would they instead swap out a known spell for the new one?

I'd let them swap. Can only know X spells at a time; kind of like how, as a kid, I could only know two or three piano pieces at a time. Every time I learned a new one, I forgot one of the old ones, LOL. Today I don't know any at all.

A really hardcore DM could suspend the rule about automatically learning spells on level-up, and instead require all spells to be either researched or learned from a teacher or written source, both for wizards and "known spell" casters. (Maybe even for clerics and druids--though you could say that the PHB spell list is hardcoded into the religious catechism of a given clerical sect, and that's why all clerics know "all" the cleric spells already.) I probably wouldn't really do that though except for wizards, because wizards are actually good at Int (Arcana) and spell research.

Bupp · Jun 15, 2017

jaelis said:
What happens if a caster with a "known spell" list, like a sorcerer, uses these rules? Would they gain an additional spell known? That seems too powerful. Would they instead swap out a known spell for the new one?

Yes, they would use these rules to swap out a spell known, or to fill a slot when they level up.

Hemlock said:
I don't know what kind of feedback you're looking for, but... these rules make spell research much cheaper and easier than what I use.

Just throwing my option out for others to check out, and use if they like. Yours look good to me as well.

jaelis · Jun 15, 2017

Bupp said:
Yes, they would use these rules to swap out a spell known, or to fill a slot when they level up.

Got it. I would give extra scrutiny to warlock spells, I guess there are some spells that could cause trouble with effectively unlimited casting opportunities.

MechaTarrasque · Jun 15, 2017

Spell research rules need something like "roll a D20. If the value is less than or equal to the level of the spell you are researching, you get sucked into the Abyss." It took thousands of tries for wizards to figure out that bat guano=fireball, but dog doodoo=uncontrollable tentacle horror from the Far Realm that sucks out your brain. You may be standing on the shoulders of giants, but they are ticklish.

Edit: maybe something like this:

1--you are teleported to Carceri
2--a Vrock demon appears that is hostile to you
3--you are teleported to the Feywild
4--a bone devil with a bad Italian accent appears to "make you an offer you can't refuse"
5--you have unintentionally cast contact other plane
6--you are infected with chaos phage
7--1d20 mephits (DM choice as to which kind) appear and follow you around loudly proclaiming you are their "Master" (good luck getting any work out of them)
8--an arcanoloth shows up and helps you with your research, and then disappears. You discover afterwards that the most valuable magic item you had is missing
9--an amorous night hag shows to help you with your research. Every time you attempt a long rest, there is a 50% chance the memories of her "help" interfere and you only get the benefits of a short rest instead. A wish or similar effect can free you of this condition.

FormerlyHemlock · Jun 15, 2017

MechaTarrasque said:
Spell research rules need something like "roll a D20. If the value is less than or equal to the level of the spell you are researching, you get sucked into the Abyss." It took thousands of tries for wizards to figure out that bat guano=fireball, but dog doodoo=uncontrollable tentacle horror from the Far Realm that sucks out your brain. You may be standing on the shoulders of giants, but they are ticklish.

I'm totally stealing this idea. A failed spell research roll needs to have horrific, adventure-generating backlash potential proportional to the power of the spell you were researching.

TheNoremac42 · Jun 17, 2017

Hmm... Our group often spends several levels at a time on a single adventure. They way we've always done it is that the spellcaster just learns their spells whenever they level up during a short or long rest. The gold spending only applies if you copy a spell into your spell book from some other medium - like a scroll or other book. From what we understand from the PHB, wizards automatically learn 2 spells whenever they advance a level. No extra research or materials required. I'm not familiar with the other spellcasting classes, but we basically do the same thing with them.