Are these homebrew attempts at recreating the Isaac's Missile Storm spells from NWN2 balanced for 5e? [Version 2]

Question

This is a follow up to my previous question: Are these homebrew attempts at recreating the Isaac's Missile Storm spells from NWN2 balanced for 5e?

In the Neverwinter Nights video game series (I'm more familiar with NWN2 specifically, which was based on D&D 3.5e), there were two spells, "Isaac's Lesser Missile Storm" and "Isaac's Greater Missile Storm". They were both (as I understand it) basically bigger, better magic missile, but with random targeting within an area. I'll also point out that my knowledge of 3.5e is exclusively from NWN2.

I liked these spells, and want to "import" them into 5e, so I've attempted to homebrew them. However, Theik's answer describes how my previous attempt was unbalanced, as well as various helpful comments under my question (now moved to chat), so I have tried to address some of the balance concerns in my latest attempt.

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There were three major problems identified; damage (especially against one single target), the amount of time it takes up resolving the randomness of it, and the fact that it only affects hostile creatures; so the things I've changed are:

• Despite wanting a "Lesser" and "Greater" version (because that's what NWN2 had), this was more of a 3.5e thing, and 5e uses the upcasting mechanic to do away with different versions of the same spell (mostly). So I've decided to stop being stubborn and reduce it down to simply Isaac's missile storm (thanks @Rorp). This was largely because I couldn't think of a meaningful way to make the "greater" version better besides just adding missiles/damage, which was part of the problem.

• Because the damage against one single target was a major problem, I have implemented an upper limit on how many missiles the spell can produce, regardless of the spell slot used to cast it. So, against a single target, it can only produce a maximum of 6 missiles. However, for each additional creature in it's AOE, it can produce 2 more missiles, but this upscaling is capped, although that cap is increased by upcasting. This, I hope, reduces it's potential against a single target, whilst still being useful against a group (thanks @BlueMoon93).

• Given that I've reduced the potential damage it can do against one target, I'm increasing the number of extra missiles it can do when upcast from 1 to 2, and the damage per missile will now be 1d6 + 1 rather than just 1d6, since that makes it strictly better than the 1d4 + 1 of magic missile; remember, an upcast magic missile at 4th level does 6d4 + 6, which is probably on average going to be about the same as the base 6d6 (if against a single target). My previous "goal" of wanting this spell to be better than an upcast magic missile remains, but hopefully this +1 per missile won't make it too much better.

• I've also decided to do away with the randomising aspect of it, as well as the "hostiles only" aspect. Fireball just hurts everyone in its AOE, and by the missiles avoiding non-hostiles, it basically became the ultimate Sculpt Spell spell, without even needing to be an Evocation wizard! So, I've changed that so that it must hit each creature an equal number of times, with some caveats that simply fall under the caster's control rather than being randomised:

  • If there are more creatures than missiles, the caster basically chooses who it hits; however, because each target cannot be hit more than once, each target will only be taking 1d6 + 1 force damage, which I think makes the "stealing Sculpt Spell's spotlight" problem minimal enough to ignore in this scenario.
  • If there are more missiles than creatures, then the decision is mostly predetermined; for example, with 2 creatures and 8 missiles, each creature gets hit by 4 missiles, but if there were actually 3 creatures and 10 missiles, then each creature gets hit by 3 missiles and the caster gets to decide who gets the extra missile. Note that non-hostile creatures are not safe from this, so this at best prevents the caster's ally (if an ally is within the AOE) from taking an extra 1d6 + 1 force damage, which isn't that big a deal given that they will already definitely be taking 3d6 + 3 anyway.

For completeness, here's a brief list of things I'm not changing, but still want to mention anyway:

• The spell level for Isaac's missile storm will be 4th level, since I'm effectively adjusting my old Isaac's lesser missile storm spell and simply removing the Isaac's greater missile storm spell (although I've given the new spell the 20-foot-radius AOE from the old greater spell).

• It still doesn't require attack rolls or saving throws, and it can still be entirely negated by shield; this means, in the case above, that it can be used in an area with an ally wizard or something, who will be completely fine because they can just shield the damage away, but because they'd still "consume" an equal share of those missiles, that doesn't mean more damage for everyone else, just none for that wizard.

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So, here's the new spell description (available only to sorcerers and wizards):

Isaac's Missile Storm

4th-level evocation

Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: Instantaneous

You fire multiple missiles of magical force that hit every creature within a 20-foot-radius sphere centred on a point you choose within range. The number of missiles is 6 if there is only a single creature within the area, and that number is increased by two missiles for every additional creature that is within the area, up to a limit of 8 missiles.

Each missile targets a creature such that each creature within the area is hit by a uniformly distributed number of missiles. If the number of missiles cannot be distributed evenly, you decide which creatures take one more missile from the remainder. If there are more creatures than missiles, you choose which creatures are hit by one missile. The missiles all strike simultaneously. Each missile does 1d6 + 1 force damage.

If the target is immune to the magic missile spell, such as by being under the effect of the shield spell, then they are also immune to this spell, although any missiles that hit such a target are consumed and cannot be redirected at a new target. Furthermore, any creature within the area that can cast shield is able to cast it in reaction to this spell as though they were targeted by magic missile.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the limit of how many missiles this spell can creates increases by two missiles for each slot level above 4th.

Is my new version of this spell balanced against other 4th levels spells, including when it is upcast (since it now produces two more missiles per spell level, but is still capped at \$6 + (n × 2)\$ missiles for \$n + 1\$ enemies)?

Incidentally, is that second paragraph of my spell description clear enough? This is where I'm trying to convey the information I gave above in my indented bullet points. Is that clear, or can it be worded more clearly? Suggestions welcome...

Answer 1

The spell is balanced but on the weaker side. It might need a push to be competitive with the popular AOE damage spells.

The missile storm is at its core, an AOE spell that has unconventional scaling based on the number of targets hit. Because of this, I compared its damage output to various spells of similar effects on 3rd and 4th level.

I used this (from u/SuscriptorJusticiero on Reddit) handy chart for the damage estimation of the saving throw fails/successes (Uses saving throw fail estimation chance of 0.66 that results in effective damage of 0.83*Full damage for spells with "save for half damage" clause).

The author claims the DMG suggests the 0.66 save failure chance, but I was not able to verify that.

Here are the results for AoE spells:

• Fireball lvl. 3: Full damage 28, Save damage: 14, Avg damage: 21, Effective damage: 23.33
• Fireball lvl. 4: Full: 31.5, Save: 15.75, Avg: 23.63, Effective: 26.25
• Ice Storm lvl. 4: Full: 23, Save: 11,5, Avg: 17.25, Effective: 19.17 (has additional CC effects)

Let's compare to blight for single target damage as well:

• Blight lvl. 4: Full: 36, Save: 18, Avg: 27, Effective: 30

Here are damage outputs of Isaac's Missile Storm based on the number of targeted creatures: ( I use a simplified way to calculate damage since the damage is uneven based on the number of creatures hit. The formula: avg. missile damage * num missiles / num creatures)

• one creature: ((1+6)/2+1)*6 = 27 damage
• two creatures: ((1+6)/2+1)*8/2 = 18 damage
• three creatures: ((1+6)/2+1)*10/3 = 15 damage
• four creatures: ((1+6)/2+1)*12/4 = 13.5 damage
• five creatures: ((1+6)/2+1)*14/5 = 12.6 damage

As seen from the results, the spell underperforms when compared to both fireballs and ice storm assuming 2+ targets in the AOE. The results are somewhat comparable for average and less so for effective damage on two targets, but the Missile storm falls off hard when more than two targets are in the AOE.

The "single target use" of the Missile Storm seems on par with the avg damage of blight.

Summary

• Missile storm underperforms other comparable spells in damage when hitting multiple opponents.

• On the other hand, Missile storm offers better damage type and consistency in damage dealt that is rare for AOE spells.

• Spellcasters can fully negate missile storm with shield but only partially negate compared spells with absorb elements

• Very useful spell against creatures with magic resistance since it does not provide saving throw

Suggested adjustments (personal opinion)

• I think the current version of Missile storm is on the edge of usability. It would be a good spell against high tier enemies that are resistant to magic but in general, it seems to get overshadowed by even lvl. 3 fireball which I consider a bad sign.

• I disagree with the author of the answer for the previous iteration on being able to select the targets for the storm. There is even a precedent with spells like Destructive Wave. I think being able to choose targets would be a flavorful addition to the spell that would push it in competition with other AOE damage staples without needing to buff its damage.

• There are other competing dualities of spells of similar purpose, where the ability to choose targets pushes the "weaker" spell to compete with the "stronger" one (see Hypnotic Pattern vs. Slow). The fact that Missile storm is 4th lvl spell also makes it a complementary option to fireball rather than a direct competitor.

• As for scaling, it would fall off even harder with 6+ targets. I am not sure a buff in this aspect is needed but a possibility would be always add 2 missiles (no missile maximum) for an additional target on lvl 4 and with casting on higher levels adding 3 missiles per additional target instead of 2 on lvl 6 and 4 instead of 2 on lvl 8. I have not done the math but it seems reasonable.

As for the clarity of the second paragraph, it is clear even if somewhat inelegant formulation, but the targeting for this spell is complex, and I can't think of a more streamlined version. A possible way would be

Each missile targets a creature. Creatures within the area are hit by a uniformly distributed number of missiles so that each creature is hit by at most one more missile than any other creature.

but that might require too much math on the part of the player to parse...

Note: I evaluate the Missile Storm for rolling a 1d6+1 separately for every missile. The damage variance for the spell would be just absurd otherwise.