Elemental strike, as per its description, grants you elemental damage with your unarmed attack (including killing hands). The DV is the same as your unarmed DV, but instead of doing Physical damage, you're doing Physical (Elemental) damage.
The rules for each element work as explained in the core book :
- Acid : According to the Core rulebook, there are two cases. Lingering acid, and Spell-based acid. Elemental strike doesn't specify it, but it should go along the Spell-based acid (remember that Core predates SG), and only deal -1 Armor with each strike, the exact same way the Toxic wave spell works.
-Acid/Cold : When there is no armor, there is nothing to strip with elemental effects. Armor accessories are in a grey area for this purpose, especially concerning Cold damage. Concerning cyberlimbs, they also are in a grey area. Allowing for Acid and Cold to utterly destroy them would be quite overpowered compared to their cost, however you can decide that
- acid only strips the armor part of the cyberlimb, possibly making all the circuitry visible (and applying a social penalty).
- for cold, same problem as armor accessories.
However, it's perfectly reasonable to apply these effects only on a called shot targeting the said limb.
- Electricity : Electricity applies whether the damage is Stun or Physical. Non-conducting armor doesn't negate electricity damage, it only adds to its armor vs Electricity damage. It applies its rating to the armor value of the armor it's installed in.
- Armor jacket (12) without special properties. Vs standard damage: you soak using 12+Bod-AP dice. Vs Electricity damage:
you soak using 12+Bod-AP dice - Armor jacket (12) with Nonconductivity[4]. Vs standard damage: you soak using 12+Bod-AP dice. Vs Electricity damage:
you soak using 12+Bod+Nonconductivity[4]-AP dice
And finally yes, if you try to hit someone with Nonconductivity using Elemental strike(Lightning), your target will have more armor, even if your damage is based out on your strength, your punch is covered with a mana-based lightning aura.
In our current campaign, I'm playing a Cold-focused mage so I can relate a lot. Concerning the armor-breaking ability of cold, we chose to apply AP to the Cold elemental effect Armor test (so if I cast Ice spear Force 4 - Dmg 4P AP-4 - against an armor jacket, it'll have 8 dice on its Armor test)
Lightning and Fire are pretty self-explanatory. For Acid, we basically ruled that every Magic-based acid source does not apply continuous acid damage, unless specifically said (Elemental Strike/Body/Weapon are included)