First, I wanted to start out by saying Baldur's Gate 3 is truly a masterpiece. With that said, I would like to share a few quick balance suggestions to improve several lackluster spells. Unfortunately, these spells felt underwhelming in most situations and there was always a better alternative. The list below is not intended to be exhaustive, but wanted to share this feedback nonetheless...
Dancing Lights * Remove concentration requirement
True Strike * Now reduces critical hit while attacking by 1
Colour Spray * Increase duration from 1 turn to 2 turns
Find Familiar * Now squeezes through and can enter small spaces * Now carries a weight up to 3 lb (low carrying capacity)
Ray of Sickness * Increase poison damage from 2d8 to 3d8 * On critical hit, target gets upset stomach condition
Witch Bolt * Reactivation cost changed from action to bonus action
Bark Skin * Now reduces bludgeoning and piercing damage by 1
Magic Weapon * Now changed from action to bonus action
Phantasmal Force * Increase psychic damage from 1d6 to 2d6
Ray of Enfeeblement * Increase range from 18m to 32m * Now casting this spell at a higher level allows an additional ray for each spell slot level above 2nd.
Vampiric Touch * Increase necrotic damage from 3d6 to 4d6
Polymorph * Instead of restricting to sheep, now adds additional creature options that scales with upcasting. By the very defintion, poly meaning “many,” so this change would make this spell multifaceted.
