D&D 5E AoE vs. Single-Target Spells

[jaelis]

Fireball and lightning bolt do extra damage because they are teh boss.

 

[Ganymede81]

I really couldn't.



But getting accused of being smart is a nice change, so thank you.

The easy way to do it would be to figure out your single-target damage, add 4/5 of that damage for the second target, add 4/5 of the previous damage for the third, add 4/5 of the previous damage for the fourth, and so forth.

That way, a spell that did an average of 10 damage per target to three targets. That'd be 10+8+6.4 for a total of 24.4 weighted damage. In other words, the spell described above would be worth the same as a spell that did 24.4 damage to a single target.

(of course, that's assuming you're comfortable with 4/5 as your weight.)

The point being that what spell is better depends totally on what you are fighting (and in general, on what kind of fights you commonly encounter).

That is not unique to the comparison of AoE spells with single-target spells, nor is it particularly relevant for balancing spells against one another.

Any individual casting of a particular spell has its utility fluctuate based on whether it will kill its target, overkill its target, or spare its target, and that fact doesn't really relate to whether an AoE spell is balanced against a single-target spell.

 

[jaelis]

That is not unique to the comparison of AoE spells with single-target spells, nor is it particularly relevant for balancing spells against one another.

Agree with the first point, not so much with the second. I think it rules out the kind of straightforward mathematical formula you suggest, and instead means you just have to playtest.

 

[Ganymede81]

Agree with the first point, not so much with the second. I think it rules out the kind of straightforward mathematical formula you suggest, and instead means you just have to playtest.

You'd think, but situational value did not stop WOTC from fitting individual spells into spell levels despite the fact that many spells are better or worse depending on the circumstances. In other words, we don't bootstrap the spell level of Fireball up or down based on the fact that most of the monsters in one campaign tend to be clustered into 20 ft radius spheres.

Sometimes PCs fight a lone foe, sometimes they fight a small group, and sometimes they fight a large group; the only thing we can reasonably do is assume it washes out somewhere in the middle and balance accordingly.

 

[jaelis]

Indeed, but I think WotC balanced the spells based on playtesting, not on an ad hoc formula. Hopefully the results of their playtesting are accurately incorporated into their spell damage guidelines. If you don't trust those, then I think you just have to do your own playtesting.

 

[Ganymede81]

Obviously, you playtest the ad hoc number to determine which one is best (I wasn't actually suggesting 4/5 is the optimal value; it was merely an example).

Certainly, WOTC did their own playtesting. What I have trouble imagining is the notion that WOTC said "ok, sometimes this spell kills a wounded ogre, but sometimes it spares him and allows him another action" or "This spell is really good against a group of rats with 5 HP each, but not very good against a group of rats with 6 HP each."

 

[hastur_nz]

I am trying to compare spells for damage output.

Why are you doing that? Provide some context, you'll get better answers. For example, are you a player trying to judge best 'bang for buck', or a DM trying to <???>

 

[Tony Vargas]

', or a DM trying to <???>

... design new spells, nerf OP ones, buff weak ones...

 

[Li Shenron]

The DMG sets the AOE damage at 75% of single target damage, and I think this works reasonably for the majority of situations.

It would also depend on the general size of the AOE... some of the PHB spells target an area of just a few 5x5 squares, meaning that most of the times you can expect to use them to hit 2 targets, unless you're very lucky. Obviously a much larger area would require to be balanced by a smaller damage.

 

[TwoSix]

In general, I usually look for about 2/3 damage for a radius 10' AoE, which I assume will hit about 2 or 3 targets. That way it's an obvious loss against one target, pretty much break even at 2 (since focus fire is generally a better tactic, even hitting 2 targets needs to be higher than 100% of single target damage), and an obviously better choice against 3.

Bigger AoEs should do less, but no less than 50% of a comparable single-target. Single targets should also tend to have better riders for their spell level.