You discharge a powerful bolt of lightning at the target, dealing
7d12 electricity damage unless it succeeds at a Reflex save. The
electricity arcs to another creature within 30 feet of the first
target, jumps to another creature within 30 feet of that target,
and so on. You can end the chain at any point. You can’t target the
same creature more than once, and you must have line of effect to
all targets. Targets after the first take 6d12 electricity damage and
must attempt a Reflex save. Roll the damage only once and apply
it to each target (halving or doubling when necessary).Success The targets take half damage.
Critical Success The targets are unaffected, and the chain ends.
Failure The targets take full damage
Critical Failure The targets take double damage.
Heightened (+1) The damage to all targets increases by 1d12.
If your enemy is far more powerful than you or a task
beyond your abilities, you might roll a natural 20 and
still get a result lower than the DC. In this case, you
succeed instead of critically succeed or fail.
So...I want to know if I'm understanding this correctly. The spell can only be ended by three things:
1. The caster chooses to end the spell.
2. There are no valid targets, meaning that there is not an un-targeted creature within 30 feat of the last hit target that does not have line of effect to the caster.
3. A creature gets a critical success, which requires them to roll a 20 and succeed naturally or bypass the save DC by 10 or more.
The DC (from what I understand) would be: 10(base)+5(a level 11 wizard should have 20 int)+11(trained prof mod)=26 Reflex
In most situations, this spell probably isnt that bad. It'll hit your entire party until the rogue or monk crits their save, if even that. It does an okay amount of damage (avg. 39 to chained targets) and half on a successful save. When this comes into play in game, it won't be a problem for the party and could be some useful AoE for the caster when his allies are all in melee and can't just fireball them all or something.
What makes this interesting is that if your wizard (or druid or sorcerer) casts this down from 500 feet onto a marching army, he could potentially obliterate most of the forces.
About what level would a normal soldier be? I didn't see anything in the Bestiary about guards or NPC soldiers, but I relied entirely on ctrl+f to search so I might have missed it. For the most part, I'd imagine that they aren't very strong, maybe somewhere around a level 1 or 2 fighter? They're probably weaker, when you consider that NPCs shouldn't be as strong as PCs, but if they're in an army they need to at least be somewhat competent.
In such a case, if we use the stats of a level 1 fighter, their Reflex Saving Throw looks something like: Roll+2(Dex, maybe more, maybe less)+2(prof mod)=Roll+4
This means that a level 1 fighter can never critically succeed on the saving throw, which means that in some circumstances, they could never stop the Chain Lightning. Logically, this makes sense. The caster has 10 levels over the NPC- it would be silly if there was a 5% chance of stopping the spell. For these NPCs, taking an average of 39 damage will kill most of them, doubling it for those who cannot even hit a 16, which, if their saves are around a +4, they won't be making most of the time, bumping the average up to overkill status. When the deceased NPC is standing right next to another NPC, walking in a rank-and-file line like a marching soldier would, and the caster is flying above the army with line of sight to the entire group, the single cast of Chain Lightning could potentially result in the death (or at least knocked into a dying state XD) of the entire army.
This is all cool and well, I actually really like it. It's a powerful spell that makes casters really strong. The only problem is that only 3 classes (other than characters who take the expert wizard spellcasting multiclass (which now that I look at, has a typo)) will ever be able to do something like this. Why is it that at 11th level martials dont get a Dynasty Warrior ability to cleave through hordes of enemies? Why do casters get the ability to turn entire armies to rubble, while a martial only gets the ability to hit harder?
As a disclaimer, like I've said before, the situation I noted above is pretty impracticable. A more practical situation where Chain Lightning could be exploited is when an evil druid attacks a marketplace or town where commoners would be living.