Trying to set up a new mechanic

[Itakai]

Hello fellow giants, I am trying to make a new mechanic for a campaign I will be running as well as balancing it out. The general idea behind this was allowing spellcasting to non-caster classes.

This is actually very important to the campaign and if it works well, I hope to use it in future campaigns.

First is a new status condition which I will call "Mind-Blank" until a better name comes up. The idea for mind-blank is pushing yourself beyond mental limits. Acquiring mind-blank causes you to become unconscious until you recover.

Secondly is the idea of a grimoire, a magical book that once read becomes blank, teaching the reader a new spell if they meet a stat requirement.



> Can cast spells beyond available spell slots (Cannot cast more prepared spells than you have spell slots for.)

> Reading a grimoire adds a spell to your spells known list, if the minimum ability requirements are met

Minimum ability requirements are The spellcasting ability of the class whose spell list it belongs to of 10 + spell level (If they are in multiple spell lists, you can select which ability to use based on which classes are available)
Spells learned from grimoires do not need to be prepared
Using a spell learned from a grimoire when having a prepared spell list will consume a prepared spell of the same level
Non-caster classes can gain spells known from grimoires.
Spells learned that are not from your spell list, are cast using the spellcasting ability of the class whose spell list it belongs to (If they are in multiple spell lists, you can select which ability to use based on which classes are available)
Upon gaining a spell from a grimoire, you will gain the ability to cast spells of that level, but will not gain any spell slots beyond 0, unless given to you by a class

> Casting spells beyond available spell slots incurs mind-blank damage

Upon casting a spell beyond available spell slots, take (Spell Level) unhealable subdual damage until next rest.
Upon becoming unconscious you recover 1 subdual damage per 5 minute.
A short rest will recover 50 mind-blank damage
A long rest will recover all mind-blank damage

> Casting spells that are not on your spell list cause double mind-blank damage.

Non-caster classes do not have a spell list and always incur double mind-blank damage.



I would love to hear some opinions on this, as like I said it is something semi-crucial to the campaign setting.

[JackPhoenix]

Mind Blank is an existing spell, I suggest using a different term.

There's no such thing as subdual damage in 5e.

The suggested idea is unbalanced as hell... great, now any caster can get access to all the spells on their list, without the preparation limit (let's not even mention spellcasters who don't prepare spells but use spells known)... and even spells from other lists. Giving non-casters access to spells won't really mitigate how much more powerful this will make actual casting classes.

50 damage healed on short rest? Great... now I cast Animate Dead 16 times to create huge undead army, take a break and continue doing the same.

What does
Using a spell learned from a grimoire when having a prepared spell list will consume a prepared spell of the same level even means? Are you actually familiar with how 5e spellcasting works?

If you really want non-casters to have access to spells, remove the requirements from using spell scrolls and make them much more common, or create similar, limited (or unlimited) use magic item.

I'm afraid some settings ideas just don't work with certain games without breaking beyond help.

[Honest Tiefling]

Spelldrain? Magefire? Spell depletion? Spellburn? I mean, if the caster is a bard or cleric, the mind might not be the first thing involved in the magic, or at least not the first thing that comes to mind.

As is, it seems weak unless you do brutal combat. Burning an HP to win a combat or encounter? If it's deadly enough, that seems like a good risk.

I think that the spell eating up a prepared spell doesn't really fit spellcasting, and is a bit clunky. Also, if I had a grimoire, I would be tempted to prepare a dummy spell for it to consume if I am a pure caster. If I am not a pure caster, handing the grimoire to the guy with spell slots to spare that's less likely to be in combat seems ideal. It makes me worry this system heavily favors casters, even if non-casters can use them.

I think a far simpler system would be to grab the ritual scrolls of 4e. Perform ritual, consume scroll. Less chance of abuse or leaving non-casters in the dust, because if they can use the scroll, they probably have a feat or ability to use rituals.

And personally, I think a ritual scroll makes more sense in game terms. You prepared that for later, as opposed to making a grimoire that eats your spells.

[Cespenar]

I suggest looking at the proposed rune casting system in Unearthed Arcana instead.