Caster questions

[Rkoskubar]

I have a player who wants to be able to merge spells together while casting to make more unique spells. Is there a class that does this,or a simple way to implement without unbalancing the game?

[Tzardok]

I think I saw a fanmade prestige class once that allowed one to "graft" spells onto each other, but I don't remember where.

The only thing in first party that I can think of that works similiar to that is the warlock. The warlock's basic attack "spell" is the Eldritch Blast, and he can modify it using different spell-like abilities: eldritch essences to change the effect, and blast shaping invocations to change the shape.

Otherwise... hmmm... let him play a spellshaper? Those creatures can cast multiple spells at once.

[Quertus]

Classically, a spell that was 2 spells put together defaulted to costing a spot equal to the sum of their levels. So Invisible in the Fog (3) = Invisibility (2) + Fog Cloud (1).

I’m not Here (6) = Invisibility (2) + Dimension Door (4) is nice, but… it could have been a Disintegrate.

I’ve never seen such concatenation to be unbalancing, and it’s sometimes fun. Researching truly novel spells, though, is more fun, if at times harder to balance.

[Kurald Galain]

You could use the Lesser Spell Synthesis feat from Pathfinder.

[StSword]

I have a player who wants to be able to merge spells together while casting to make more unique spells. Is there a class that does this,or a simple way to implement without unbalancing the game?

It's a third party pathfinder class, but yeah someone did that.

Samurai Sheepdog's Thaumaturgist from Lands of Theia.

They have spell synthesis- If spells share at least two of the following traits- School (including subschools), all descriptors, casting
time, range (greater than personal or touch), area or targets, duration, or saving throw.

At fifth level they can choose spells, and prepare the combined spell in a spell slot of 1+combined spell levels.

As they level up, they can combine any number of spells including combined spells, metamagic adjustments (applied to the individual spells or the entire combination, but it has to be applicable to all the spells if its the latter), as long as they can prepare spells of the resulting spell level.

Magic Missile/Lightning Bolt would be a fifth level spell, at 15th level a thaumaturgist could cast a maximized magic missile/lightning bolt.

Likewise a burning hands/magic missile/shocking grasp would be a fifth level spell, a quickened burning hands/magic missile/shocking grasp would be a ninth level spell.

Cure light wounds/cure moderate wounds would be a fourth level spell, that could be further synthesized to make (cure light wounds/cure moderate wounds)/cure serious wounds as an 8th level spell.

Edit- There's also the Theurge (https://www.d20pfsrd.com/classes/3rd-party-classes/kobold-press-open-design/theurge/)class, which can cast two spells at the same time a limited number of times a day, I'm not sure if that's close enough.

[Asmotherion]

Well, that's the basic concept of the Arcane Fusion spell, only available to Sorcerers.

[Anthrowhale]

Well, that's the basic concept of the Arcane Fusion spell, only available to Sorcerers.

This seems spot on.

Another way to do this is via Repeat Spell, which allows the second spell to have different parameters from the first. For some spells which have multiple possible effects you can achieve two-spells-in-one although with a round delay on the second.