Spell Combat with a held charge vs casting a spell

Question

My level 1 Magus has cast Shocking Grasp during the first round and missed his touch attack so is still holding the charge. On his second turn, can he use Spell Combat to attack with the spell in his offhand as well as taking a melee attack with his weapon?

Spellstrike (a level 2 feature) is not involved in this question at all. This is about whether Spell Combat can be used without actually casting the spell during the full round action if the spell is already being held in hand. Do I have to literally cast a spell during the full round action in order to qualify for spell combat or would holding a spell charge be enough?

I'll need a full RAW answer to either confirm or overturn the ruling at the table (which I will not describe in order to leave the answer unaffected).

Note: I understand that at level 2, with spellstrike, I can deliver touch spells through my weapon. However, there is absolutely no interaction between that ability and this question.

Answer 1

Spell combat doesn't apply after a level 1 magus casts a spell

The level 1 magus extraordinary ability spell combat, in part, says

At 1st level, a magus learns to cast spells and wield his weapons at the same time. This functions much like two-weapon fighting, but the off-hand weapon is a spell that is being cast. To use this ability, the magus must have one hand free (even if the spell being cast does not have somatic components), while wielding a light or one-handed melee weapon in the other hand. As a full-round action, he can make all of his attacks with his melee weapon at a –2 penalty and can also cast any spell from the magus spell list with a casting time of 1 standard action (any attack roll made as part of this spell also takes this penalty).…

(Emphasis mine.) As the boldfaced text above indicates, the extraordinary ability spell combat no longer applies if the magus, for example, cast a touch spell last turn and subsequently missed with that touch spell's charge. Nonetheless, this turn the magus may still hold last turn's already-cast spell's charge, but the extraordinary ability spell combat no longer interacts with that spell as the spell's already been cast.

Answer 2

No.

You cannot deliver a held charge in place of casting a spell during spell combat. To deliver a held charge, you must perform one of the following actions:

1. Melee touch attack as a standard action.

2. Unarmed strike or natural attack

3. Weapon attack using the spellstrike class feature

Spell combat says you cast a spell as part of the ability. Since none of the above actions are a spellcasting action, you cannot deliver a held charge in place of casting the spell during spell combat.

Answer 3

By RAW, You would have to cast the spell again, but you have options.

There are a few relevant lines in Spell Combat:

This functions much like two-weapon fighting, but the off-hand weapon is a spell that is being cast. (d20PFSRD - Spell Combat Emphasis mine)

As a full-round action, he can make all of his attacks with his melee weapon at a –2 penalty and can also cast any spell from the magus spell list with a casting time of 1 standard action (any attack roll made as part of this spell also takes this penalty). (d20PFSRD - Touch Spells in Combat Emphasis mine)

This clearly states that the function of Spell Combat is to allow the casting of a spell to function as a second "weapon," not the spell itself.

All is not lost

Your first option is to just use the normal Two-Weapon Fighting rules on your next turn. This is because:

Alternatively, you may make a normal unarmed attack (or an attack with a natural weapon) while holding a charge. In this case, you aren’t considered armed and you provoke attacks of opportunity as normal for the attack. If your unarmed attack or natural weapon attack normally doesn’t provoke attacks of opportunity, neither does this attack. If the attack hits, you deal normal damage for your unarmed attack or natural weapon and the spell discharges. If the attack misses, you are still holding the charge. (d20PFSRD - Touch Spells in Combat Emphasis mine)

So if instead of using Spell Combat you simply use Two-Weapon Fighting and include an unarmed attack (and it hits) you get to discharge the spell you are holding.

Your next option is this feat, though it is third party and hence up to DM discression:

When holding a charge from a touch spell, you can choose not to have the spell take effect when you touch someone or something. You can cast other spells while holding a charge. If you cast another touch spell, you cannot hold the charge on the newly cast spell beyond the end of your turn, but you may deliver both that spell and the held touch spell in a single touch attack. You lose the held charge if you become unconscious or when you normally replenish your spells. (d20PFSRD - Touch Spell Control Emphasis mine)

This would allow you to just dive straight back in to Spell Combat.