Larian Studios Forums Baldur's Gate III Baldur's Gate III - Build Discussion Multiclass mechanics

Is this a trick question? Chain Lightning is a 6th level spell you can only gain at level 11. It's not possible to do what you ask.

Edit* No, its possible since spell slots are based on character's total caster level. It would be Intelligence since you would require to learn the spell via Wizard scroll feature.

Also if you choose the same spell say Witch Bolt for multiple classes you'll have a choice to choose which class to cast the spell from for that spell. So if you have Witch Bolt for Sorcerer and Wizard you can cast that spell with Cha. or Int.