Wizards/Priests/Druids are limited to at most 2 casts per level per class per encounter. Overall, multi-classing seems to give you one extra cast per encounter... a slight benefit.
Sure, spells would almost always work better with two casters rather than one, with the exception of self-only buffs. Most of the subclass bonuses only apply to spells from that class (Druid Fury's penetration bonus only applies to Druid elemental spells... although Wildstrike elemental bonuses do apply to all). But the Wizard self-only buffs are really good. So's Spiritshift Cat Form (+33% speed, stacks with Dexterity Inspirations like Wizard's) and the "radius of caster" druid and priest spells. Priests also have the summoned weapon with the long casting time that's otherwise pretty good... and you could technically speed up the casting time by multiclassing Wizard or maybe Cat druid, though I'm not sure what happens if you summon a weapon while spiritshifted....
Yeah druids will probably be the most viable dual caster class due to its martial abilities that can synergize with buffs. Priest/wizard or multidruid multi classing druids that does not want to focus on physical attacks in spirit form will have a harder time though. Iam begining to lean on multiclassed casters having fewer class resources (ie. fewer spells per encounter) rather than having lower spell levels on their casts since then you won't have to worry about the spell synergy. However, if there are some super powerful self buffs there will probably be some crazy class synergy between a physical and caster class that might end up too powerful, which would be a major risk with this approach. Still if the objective is to make every kind of character viable this might be the best approach.
Currently spells have two major limitations:
- Most spells have slow casting speed
- They tend to miss (usually Accuracy vs. Fortitude/Reflex/Will) and most can't graze (though some long-casts like Fireball can)
So buffs which improve casting speed and don't take long to cast are very useful. Cat Druid Flurry = instant +33% speed, Wizard Fleet Feet quick cast 0 recovery +5 dex = +15% speed that stacks with the Cat Druid bonus.
Wizards have Eldritch Aim to help with Accuracy (and grant grazing for all spells).
There are very few fast cast damaging spells, and they're all level 1 or 2. Single class Wizard has maximum 2 (or 4 if you count Grimoire Slam) per encounter, single class Druid has 2 / encounter, multi-class has 4 to 6....
Likewise, most of the Priest subclasses get either some Wizard or some Druid spells... so if you multiclass, you could get 2 priest casts of the spell and 2 wizard/druid casts of the same spell per encounter.
Edited by SaruNi, 06 December 2017 - 01:35 PM.