Based on the original question from before, see it for some of the feedback considerations. The quick version is that this is intended as a hybrid of the chromatic orb and green-flame blade spells. Between the previous feedback and talking to the player about their intentions with the spell the focus has changed a bit. Instead of my interpretation of it being a melee-AOE spell (melee + cone effect or similar) he'd prefer if it was more of a smite with just a sprinkling of AOE damage instead of a secondary effect (bigger damage boost single target with just a little spread). So, here's the revised write up of the spell:
Casting Time: 1 bonus action
Duration: Concentration, up to 1 minute
When you cast this spell you choose acid, cold, fire, lightning, poison, or thunder and temporarily imbue your weapon with that element. The next time you hit a creature with a melee weapon attack during this spell’s duration, you release the element stored by the spell, and the attack deals an extra 3d8 of the chosen elemental damage to the target. Additionally, some of the elemental energy can strike one creature that you can see within 5-ft of the initial target. The second creature takes damage of the elemental type equal to your spellcasting ability modifier.
At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the melee attack's bonus elemental damage increases by 1d8 and the elemental burst can affect one additional adjacent creature for each slot level above 2nd.
Wording clarifications for reading purposes
The combined verbiage is a little awkward frankly. There are components from chromatic orb, green-flame blade, and the paladin smites (i.e. burning smite and branding smite specifically). There's a bit of a mismatch trying to add the elemental choice and the additional targets specifically. The intent is 1 melee target gets the bonus 3d8 chosen element damage and one additional adjacent target takes elemental damage equal to the caster's spellcasting modifier. Upcasting adds 1d8 to only the initial hit on the melee target and 1 additional adjacent target being affected by the extra burst damage (so L3 would be 4d8 bonus on hit, 2 adjacent targets taking spellcasting modifier damage, etc.)
This is most directly comparable to blinding smite in that they both deal 3d8 bonus damage with some kind of secondary effect. The ability to pick the elemental damage dealt is already rather strong so I wanted to leave the AOE rather weak and thus made it more similar to green-flame blade's "one additional target" type verbiage instead of making it a cone effect like before. The ability to choose the element plus the bit of splash damage dealt is what I'm mainly trying to balance against the, sometimes rather powerful, secondary effects of the various smites. Back to the direct comparison of blinding smite, a creature that fails its constitution save is then blinded until the spell ends (a near universally powerful affliction unless the creature has tremor sense or blind sight).
The other main complication was what to do with the spell when being upcast. Green-flame blade being a cantrip only gains additional effects/damage every 4 levels or so but most spells allow for benefits on every or every other level. A single 1d8 bonus on the main hit seems fine but I didn't really want to add an additional 1d8 to the second target as then it would scale much, much faster than green-flame blade (granted that's comparison a 2nd level spell to a cantrip).
Example turn damage comparisons
Let's assume a 7th level Eldritch Knight (the character in question who proposed the spell) using a longsword + shield with +4 strength and +3 intelligence is considering their options to attack a melee target during a turn (each ignoring AC as they're all melee attacks and thus have the same chance to hit):
Casting chromatic smite as a bonus action, Green-flame blade as the action
- Total Damage: 2d8 (2x longsword) + 8 (2x str mod) + 3d8 (elemental choice) + 1d8 (fire) on target with additional 1d8 (fire) + 6 (2x spellcaster mod bonus) on 2nd target for a total of 7d8+14 damage, averaging 46 damage depending on resistances.
- Pros/Cons: 2nd level spell slot, 10 damage average requires a second adjacent target be present, can pick the type of half the damage applied, opportunity cost of maybe a second wind or similar
Casting chromatic smite as a bonus and two attacks as their action
- Total Damage: 2d8 (2x longsword) + 8 (2x str mod) + 3d8 (chosen element) on target with 3 (spellcaster mod bonus) on a 2nd target for a total of 5d8+11 averaging 34 damage
- Pros/Cons: 2nd level spell slot, 3 requires secondary adjacent target, can pick the type of more than half the damage, opportunity cost of bonus action
Green-flame blade as their action and using their War Magic feature for a melee attack as a bonus
- Total Damage: 2d8 (2x longsword) + 8 (2x str mod) + 1d8 (fire) on target with bonus 1d8 (fire)+3 (spellcasting modifier) on secondary for total of 4d8+11 averaging 29 damage
- Pros/Cons: no spell slots used, 7 damage requires adjacent secondary target, damage is all slashing or fire so more commonly resisted, opportunity cost of bonus action
Two attacks as their action and "something else" as their bonus
- Total Damage: 2d8 (2x longsword) + 8 (2x str mod) for average of 17 slashing damage
- Pros/Cons: no spell slots used, can do whatever you are able with bonus action, considerably less damage than previous options (really once you're at this level there's not a great reason to not use green flame blade each turn as long as you don't need your bonus for something else)
There's also potential to take some action on a turn and cast the smite as a bonus ahead of time if it can't be immediately used (no targets within movement, for instance). This is much more open ended though so very hard to consider and requires maintaining concentration on the spell until a melee strike is made (though an Eldritch Knight will be proficient with presumably a decent constitution modifier).
Did I miss any important situations in my generalizations above?
- See previous question linked initially in this one for most of the previous considerations
- If the splash damage is too weak/doesn't scale well it could be increased. Making it scale every level seems like too much though and making it something like every X levels just adds complicated wordings into the spell somewhat needlessly
- If the main spell damage is too much I could maybe drop the damage dice/number of dice. It seems on par to other smite spells best I can tell and might even be slightly underpowered depending on how much weight can be given to the ability to pick the damage type.
- Could perhaps raise/lower the spell level if it seems too strong/weak. The intended target spell level was 2nd level, hence the immediate comparison to branding smite, and meant for an Eldritch Knight
Overall, how is this homebrew chromatic smite spell balanced? How could it be improved?