When a magus makes a successful hit with spellstrike, it is ambiguous whether the weapon damage resolves before or after the effects of the spell.
If successful, this melee attack deals its normal damage as well as the effects of the spell
A similar RPG Stackexchange question from 2013 asks whether the order is specified by the rules, which it is not, and the accepted answer recommends that the GM arbitrate. I am asking whether the magus can, at the same time they make the spellstrike, choose this order.
There are scenarios where it would be advantageous to resolve the weapon damage before the spell, and vice versa:
Example 1: Alice the magus uses spellstrike to deliver vampiric touch against Bob, who is at low HP. Depending on how much HP Bob has left, Alice would regain some temporary HP from the vampiric touch effect:
You can’t gain more than the subject’s current hit points + the subject’s Constitution score (which is enough to kill the subject).
If the weapon damage resolved first, Bob would have less HP remaining before the vampiric touch resolves, and Alice would get less temporary HP. Whereas if the vampiric touch resolves first, Alice could get a lot of temporary HP, and then the weapon damage would resolve.
So in this case, Alice wants the spell effect to resolve before the weapon damage.
If the weapon damage resolved first, Bob might be shaken, and take a -2 penalty to that saving throw, which means Bob is more likely to fail against the spell. So in this case, Alice wants the weapon damage to resolve before the spell.
Can the magus choose which one resolves first? Or does this power lie with the GM? Or is there some errata or FAQ that I have overlooked?