Honestly, this spell was my Eldritch Knight player's idea but I thought it interesting and am trying to work out the balance. It's sort of a hybrid of the chromatic orb and green-flame blade spells.
The idea is to imbue chromatic orb's ability to pick the element, a powerful ability, into a melee attack with similar-ish splash damage. Something akin to the dragon's breath spell's short-range cone felt right.
Casting Time: 1 action
Range: 5 feet
Components: V, M (a weapon)
Your weapon gleams with incandescent light. You choose acid, cold, fire, lightning, poison, or thunder for the type of glow you create. As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell's range, otherwise the spell fails. On a hit, the target suffers the attack's normal effects, and elemental energy of that type bursts forth from your weapon in a 5-foot cone directed at the point of attack. Creatures within the cone's area of effect take 2d6 damage of the chosen elemental type.
At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.
Wording clarifications for reading purposes
"Incandescent" tends to mean "glows from being heated" (like an incandescent light bulb). The nearest alternative I could think of was radiant, and while I think that's a better fit semantically, that is already its own damage type (and intentionally not one of the options here to keep in line with chromatic orb). I could just say "chromatic light", but chromatic is just the light spectrum already so that's lame/nonsense.
"directed at the point of attack" is a little awkward, but the intent is "from you in the direction of the attack". Unsure on the best wording there to represent this.
"Cone of 5-ft. radius": The intent of the spell is to represent an area like so:
| | |X| |O|X|X| | | |X|
With the O being the caster, and the Xs being the targets. So the cone would include the hit target of the melee attack (like green-flame blade) and proceed to jump to the 3 adjacent/back tiles (back, diagonal up, diagonal down). If there's a better way to word that part in general, I'd be open to it.
My thinking was that being able to pick your element is a powerful feature of chromatic orb, and giving it an AOE effect both warranted it dealing less direct damage than the nearest equivalents (1 casting of chromatic orb and 1 spray of dragon's breath). Math comparisons of similar abilities/attacks/spells:
- chromatic orb: 1st-level spell, does 3d8 of chosen type to a single target based on spell attack roll (averaging 13.5 on a hit)
- dragon's breath: 2nd-level spell, does 3d6 per breath (average 10.5 per target) but with a save so at least some guaranteed damage (average 5.25 on a save per target) and across a 15-foot cone (bigger area than proposed)
- dragonborn breath weapon: once per short rest and character-specific (like from a red dragonborn), does 2d6 of your draconic ancestry's elemental type (average 7 per target) with an associated save for half damage (average 3.5 per target) for a 5-foot cone (same area)
- scorching ray: 2nd-level spell, 3 individual ranged attack rolls for 2d6 fire damage per hit (average 7 per hit)
- green-flame blade: cantrip, melee hit + fire damage on additional creature within 5 feet based on your spell modifier (1-5 realistically)
All of the above scale to include an extra damage die per level, or in the case of green flame blade, being a cantrip, at select player levels.
- Could perhaps use a save for the elemental damage, Dex or Con
respective to the element chosen like normal)
- Pro(s): fits closer to the dragon's breath spell's damage per target (also 2nd level)
- Con(s): spell already requires a struck melee attack before it does anything and that then means its a roll per target, which I know lots of spells do but just adds to the complexity of the mechanics
- Could make it just a single additional target within 5ft of the melee
- Pro(s): Would make it fit a little closer to Green Flame Blade's effect
- Con(s): then the damage at face value seems a little underwhelming being 2d6 per target (though in its current form of not needing a secondary save for each target in the cone, it's potentially up to melee weapon + 8d6 damage in total, compared to 6d6 for all 3 rays hitting for scorching ray, and you get to pick the damage type for this, though a more realistic situation of melee target + 1 extra is melee + 4d8 chosen damage)
Could increase/decrease the damage dealt or increase the range if the damage seems right but maybe not enough AOE (more similarly scoped to dragon's breath spell, also 2nd-level)
Overall, is this homebrew chromatic blade spell balanced? How could it be improved?