Breaking Magic Trick (Fireball) for massive damage - Explosion!

[Serafina]

So Magic Trick (Fireball) get sometimes talked about, for example in Iluzry's fantastic Sorcerer guide.

It has two really nice tricks, but here we are going to talk about how combining them, with Widen Spell, just breaks it in half. The above guide already mentions that, I just want to elaborate on that because, like, dang.

TL;DR: This more than doubles the damage of Fireball, while allowing you to very selectively pick off targets (and always have very big fireballs ready if needed at the same time, too)

So, what are we dealing with here?

• Cluster Bomb splits your Fireball into a lot of smaller fireballs, each of which deal 2D6 damage on their own and have 10-foot radius, but can overlap and only allow a single save. So if you just make them all overlap, that's basically a smaller fireball but with no damage limit, which is good!
• Concentrated Fire allows you to shrink your Fireball by 5-foot increments, in exchange for +1D6 damage each time (breaking the damage cap too). It requires that you know Widen Magic (or Selective Magic).
  Yes, those stack.

Yes, those stack.
But what if we were to just Widen the Cluster Bomb, and then Concentrate it?
A Widenend Cluster Bomb Fireball has a 20-foot radius. We shrink that to 5 foot, and thus gain +3D6. Now our Cluster Bomb deals 5D6 damage - for each Fireball we get.


What does that look like in practice?

Take your typical Blaster-Sorcerer at 10th level. A Bloodline that adds +1 damage/dice, and Blood Havoc for the same. They have one Metamagic Reduction feat, for Fireball, because the GM limited them to one of those. Thus, they can cast a Widened Concentrated Cluster Bomb Fireball at 10th level, three times per day.
Each individual Cluster Bomb deals 5D6 + 10 damage, for an average of 27.5. At CL 10 or 11, they get five such cluster bombs - so if they want to nuke one enemy really hard, that enemy takes 110 damage.

Let's level them up to level 16. The spell gets Empowered (with a Rod), and either Maximized, Persistent or Piercing for more consistent damage. Also, there's 8 such cluster bombs now.
41.25 average damage per Cluster bomb - and 330 damage total.

The absolute utmost you can get out of this is at level 20, with three stacking bloodline arcanas and two metamagic reduction traits, for ~660 damage.
And of course usual blaster-optimisation applies - you can admixture this, turn it into Sonic Damage via Choral Support, and so on.


But high-end optimisation aside, I think the most notable thing about this is just

• how early this is available - 7th level if you have two metamagic reduction traits and are a Wizard, or 10th if you don't
• how blatantly this is signposted, given that Widen Spell is literary a pre-requisite for one of the tricks
• how flexible this keeps you, given that you don't have to apply the tricks, and that you can still individually spread the cluster bombs out to hit smaller enemies as needed

As usual, I'm not recommending that people use this to break games.
Without anything to add much extra damage, in a decently optimised party, this can just be a cool trick. If your party is very high OP, this may work well on a Blaster-character. The high end seems like a bit much for nearly all games, but still deserves to be talked about.

[Kurald Galain]

It's a good trick. Also, I don't think it will actually break games all that much.

Like, at level 10 the baseline is Empowered Scorching Ray (assume +1 damage from bloodline, +1 caster level from whatever) for 12d6+12 * 1.5 = 81 damage with no saving throw. Now 110 damage is clearly better than that, but it requires investment and is not so much better that I'd consider it game-breaking. So I'd say go for it.

The real cheese here is those metamagic reducing traits

[Serafina]

Oh, that sure is good to keep in mind, yes.
I think the real danger comes around at higher level or more optimisation, because there the scaling gets way better.
So this basically amounts to a warning to keep things in check.

Like, it's probably fine if you use it without too much extra stuff, and using something like e.g. Empowered Maximized Intensified Battering Blast would be okay too (~292 force damage).
Doing ~50 more sonic damage than that won't break the game at our level 16 example - you'll have the flexibility to hit an area, but that'll be fine? And Touch-AC vs. Reflex and such depends on the game.

But Fire-Damage is extremely easy to optimise, even when turned into Sonic via Choral Support (and if that's banned, it'll be a binary matter of "does this spell work or not"). Cross-Blooded for Solar Bloodline would be easy to do, you can dip Bloodrager and grab Flumefire Rage - that's a lot of extra +1's. Then there's means to inflict fire vulnerability, and some other stuff.

If someone were to go all out with that, and have extra metamagic reduction (allowing that), they'd do 5D6+25 damage per cluster bomb, for ~212 damage at level 10 (5 bombs).

By comparison, a Scorching Ray with the same parameters would do 12D6+60 x 1.5 = 102 damage. A lot, but a lot more manageable?

And it's at that point of optimisation where I think you can call it game-breaking, because that's still doable several times a day by level ten.
It's pretty trivial to Just Not Go There, as a player - either not do the concentrated cluster bomb trick, or don't stack so much damage adding on top of that.


Also I sure agree that Metamagic Reducing Traits can get very silly - I intentionally used an example where a GM goes "no those don't stack!", but it was still silly.