First off, I bet this has already been discussed, but I couldn't find a thread - my apologies if I'm beating a dead orc.
One of players in the game I run just brought in a Magus, and I'm slightly uncertain on how to make a ruling on Spellstrike:
Spellstrike allows Magus to deliver his touch attack spell (say, Shocking Grasp) via a regular (weapon) melee attack. My problem is on how to reconcile that with touch attack.
Say Magus takes a swipe with his Shocking-Grasped-Sword at a Fighter in heavy armor. Would Magus roll one attack roll (against base AC) and apply both weapon and spell damage if it hit, two (one VS base AC, another VS Touch AC) and apply whichever hits (or both or none), or roll once and apply either sword and spell or spell only, depending on whether the attack hits high enough to blow through armor, or just "touch".
RAW, it seems to me like scenario A is the case : One roll, either you blow through armor or there's no damage. I'm leaning towards scenario C: one roll, you apply sword damage if roll is high enough for armor AC, spell damage if roll is high enough for touch.
(On a semi-sorta-unrelated note: How would you say Shocking Grasp's +3 to hit VS metal-carrying targets affects Spellstrike?)
No, to deliver through the weapon there is a trade. You are giving up the ability to hit only the target's touch AC for using the weapon's crit modifier.
He can either use the touch attack that comes with the spell, or hit a normal ac and get a 19-20 crit range (usually). If the weapon crits, so does the spell.
(Only vs. a target in metal armor, but yes.)
Say Magus takes a swipe with his Shocking-Grasped-Sword at a Fighter in heavy armor. Would Magus roll one attack roll (against base AC) and apply both weapon and spell damage if it hit
Yes, one attack vs normal AC, with the +3 if the target has metal weapon/armor.
You may find this Guide to touch spells, Spellstrike, and Spell combat useful.