[SmilinIrish]

So there are a couple of things that give up Damage Value for Armor Penetration.  Whether a called shot, ammo type, or metamagic, it seems that unless you are getting more than 3 AP for giving up 1 DV, it isn't worth it.  AP reduces the Armor Value of the opposed roll.  It takes 3-4 dice on average to soak 1 DV.  How is this good?  Granted, I guess that reducing the DV can turn damage from stun to physical, but that rarely matters to a runner, as they aren't worried about how long the enemy takes to heal. 

And this metamagic for example: 

PENETRATING SPELL (street grimoire)
With this metamagic, the magician can choose to increase a Combat spell’s AP at a cost of reduced damage before casting the spell. Reduce the DV by 1 for every point of AP increased, up to the Force of the spell. Minimum damage is 1. Drain Value increases by 1 for every point of AP increased. For example, a Force 5 Fireball spell (normally with a DV of 5P and AP –5) is modified to have a DV of 3P and AP –7 before the spell is cast; since the AP was increased by 2, the normal Drain Value is then increased by 2. Net hits are then applied to either increase the Damage Value or reduce scatter, as normal (p. 283, SR5).

Not only are you needing to give up 3 DV to equal one less soak, you take extra drain for it.  Was this something that worked in 4e and now sucks in 5e?

Tell me I'm missing something.

[Jack_Spade]

You are correct for the most part.

There is only one specific case where this does not apply: Hardened Armor
Every two points of AP you get reduce Soak by about 1.66 and in addition enable you do damage at all if your damage previously did not exceed the armor value of your target.

Penetrating spell is garbage though. Increasing Force on an indirect spell raises AP as well as damage. That's a better bargain for the increased drain. Once you max out at F12 you likely have other problems and should probably switch to direct combat spells.

[SmilinIrish]

Maybe I'm dense, but if you are giving up DV for AP at 1:1, how will that change the point at which your DV exceeds their modified AV?  12P vs their AV of 14.  10P vs their AV of 12...if its a 1:1 trade...

[SunRunner]

Until and Unless your getting 3 or 4 AP per DV lost its not worth it. Hardened armor is the only time it can be worth it and that is questionable in all but a few corner cases. The big thing to remember about hardened armor is you get 1/2 your armor value as automatic successes on the damage resistance test. So if your fighting something with 20 hardened armor they have 10 successes on the damage resistance test before they even roll dice. That is were going from 20DV 0AP to say 18DV -2AP might be worth it as you have knocked them down to 18 hardened armor which means they only have 9 auto hits and 18 dice + body on the actually roll. Mainly because your double dipping and reducing how many dice they have as well as reducing auto hits, even then its not worth it 90% of the time.

Most of those effects are worthless and the the AP meta magic is so Mathematically bad its hilarious and I think they honestly put it in the book as a joke just to see if anyone was stupid enough to take it like ever in the history of shadowrun 5E.

[Mirikon]

Like many such things, it is situational in its usefulness. Hardened Armor is the big one, of course, since giving up two points of DV knocks off three points of resistance and makes it easier for you to actually damage the target. But other situations where it is useful would be when dealing with heavily armored drones (where you cant switch to Direct spells, and they laugh at Stun damage), and when you're concerned about 'overkill' (a change in DV for AP may work out better for trying to take a target down, if you can get Stun damage instead of physical but low force spells might not do enough damage). Also, when you apply it to AoE combat spells, it does the tradeoff for all targets, which can have nice effects.

It is a very niche quality, though.

[Jack_Spade]

@Mirikon

Powerbolt is actually a pretty decent way to deal with drones through a direct damage spell, due to drones usually having less damage boxes and relatively low body. Especially coupled with Witness My Hate.

Maybe I'm dense, but if you are giving up DV for AP at 1:1, how will that change the point at which your DV exceeds their modified AV?  12P vs their AV of 14.  10P vs their AV of 12...if its a 1:1 trade...

You misunderstood me: Penetrating Spell will never be good. It's mathematically impossible. It would be decent if it kept damage steady and increased AP with added drain, but written as it is, there is just no reason to take it.

[Marcus]

Hardened armor is the easy case but its not the only case. If an effect requires you to actually do damage to trigger the effect, even if that damage is less then it could have been so long as the trigger effect is worth the loss then it can still make sense. Various Injection vector Poisons come to mind. I do think there is a good case for DV to AP, given that spirits are a serous thing in SR. But in generally I think it's more to hit for AP, which is arguably the same thing so long as we are talking 3:1 on average.