What Breaks if 3.5 Used 5E's Multiclass Casting System (and Has Anyone Done It?)

[EndlessKng]

I know that Unearthed Arcana tackled part of this with the Magic Rating - making casting level for power purposes based on a collective score from all classes, each contributing a different value. However, i am more curious about what would happen if we used the spell slot chart as in 5e - where your total caster level determined the number of slots you got.

Obviously I'm seeing several issues off the bat - different casters used different structures for their charts, with spontaneous getting more than prepared in general and divine prepared having more than arcane prepared. There's also the issue of preparing versus spontaneous casting for the allocation of slots, since 5e took a different approach and made everyone have a limited spell known pool but gave Wizards preparation and a spellbook. However, those may be surmountable issues by simply using the same structures - which could serve to bring Clerics and Druids down a power tier (but maybe too much so) by shifting to the 5e casting whole hog, while keeping other structures the same.

But is this viable? Or are there other balance issues that this doesn't consider? And has anyone published or posted a system that works like this (not looking for something like Spheres, I do know about that but I'm more focused on this specific structure)? Just trying to see whether it is even a viable idea.

[NigelWalmsley]

I doubt it would accomplish much. IIRC, 5e seems to expect mutliclassed casters to rely on Upcasting, which 3e casters don't get. You might get some number of Mailman-style metamagic blasters swapping over to other classes for utility magic, but mostly you'd be better off just taking a Theurge PrC.

[Edea]

To tack on to the upcasting idea, even with metamagic in play: D&D 3.5 high-level spells are not D&D 5e high-level spells. Missing out on 9ths, or even delaying 7ths and 8ths in 3.5, sucks. In 5e, however, you just need the 9th level slot (singular, lol); after that it's not overly relevant unless you're specifically a Wizard (hell, as a Sorcerer you're probably better off chewing the slot for more sorcery points, given how few spells known you get).

[Biffoniacus_Furiou]

Believe it or not, 3.5 already has exactly the same thing when you compare equivalent game mechanics.

In both 3.5 and 5e the level of spells you can cast is still dependent on your level in each class, it's identical.

In 5e there's no such thing as caster level, instead spells scale with the level of the spell slot spent to cast it. There's no other use for higher level spell slots (apart from Smite and a few other niche non-spell uses) other than making your spells scale to have a stronger effect. This is why it keeps up with your character level when you multiclass. In 3.5 the equivalent mechanic to this is caster level, which you can use Practiced Spellcaster to keep up on when you multiclass. So in both games, the system in place is 100% to make your spells continue scaling with character level when you multiclass. The mechanics are called different things, but the end result is identical.

[NigelWalmsley]

To tack on to the upcasting idea, even with metamagic in play: D&D 3.5 high-level spells are not D&D 5e high-level spells. Missing out on 9ths, or even delaying 7ths and 8ths in 3.5, sucks. In 5e, however, you just need the 9th level slot (singular, lol); after that it's not overly relevant unless you're specifically a Wizard (hell, as a Sorcerer you're probably better off chewing the slot for more sorcery points, given how few spells known you get).

D&D 3e just has faster power scaling (particularly for casters) than 5e does. Missing even a single level of casting progression is very punishing from whenever you miss that level to the end of the game.

[VladtheLad]

I think trailblazer did something similar, as did Kirthfinder.

[stack]

It would be nice for casters trying to enter theurge prestiges and give a bump to the value of heighten spell for such classes. The most powerful casters won't see much change.

[Gnaeus]

It would be nice for casters trying to enter theurge prestiges and give a bump to the value of heighten spell for such classes. The most powerful casters won't see much change.

I think it will certainly help low op builds way more than high op ones. Something like Paladin 4/Cleric1 or Ranger 4/Druid 1 is just better.

Before (assuming wisdom bonus), you had 1 level spell from the half caster, and 2 from the full caster.

Now you have 3 level 1 slots and 2 level 2 slots, so 5 spells vs 3, 2 get free metamagic if you have the feats, and could prepare L1 spells from either list.

It’s still inferior to cleric or Druid 5. But less so.

[ciopo]

I doubt it would accomplish much. IIRC, 5e seems to expect mutliclassed casters to rely on Upcasting, which 3e casters don't get. You might get some number of Mailman-style metamagic blasters swapping over to other classes for utility magic, but mostly you'd be better off just taking a Theurge PrC.

3.5 has upcasting for prepared spellcasters (and there is an argument to be made for spontaneous, there it's ambiguous), but it just serves no general purpose unless you like that lower level spell more than whatever higher level you could prepare instead

[Wildstag]

Psionics would be shafted since you'd need to create 5e-like Psionic rules for multiclassing. Granted, psionics already has upcasting somewhat, so there's less issue with that mechanic interaction.

Multiclassing wouldn't necessarily break some of the classes, but you'd see a lot less usefulness out of it. The saving throw multiclassing aspect would have to be reworked, since with 5e you don't get the new class' saving throw proficiency, which might translate to their save progression. Skills wouldn't appear on your list, so some builds might not be viable.

[NigelWalmsley]

3.5 has upcasting for prepared spellcasters (and there is an argument to be made for spontaneous, there it's ambiguous), but it just serves no general purpose unless you like that lower level spell more than whatever higher level you could prepare instead

Eh. It's not really fair to call that Upcasting since, as you note, you don't get anything for doing it. The fact that you get an effect that is at least nominally "bigger" in some important fashion out of a higher level spell slot is core to the concept.

[stack]

You could give heighten spell for free so you at least get a DC boost.