Channel Spell (su) and Scorching Ray

Question

When talking with my players (we all play Pathfinder, but use some classes of 3.5), one of them plays with a spellsword and we're confused about channel spell:

Channel Spell(su) At 4th level, a spellsword can channel any spell he can cast into his melee weapon. Using this ability requires a move action, and the spellsword uses up the prepared spell or spell slot just as if he had cast the spell. The channeled spell affects the next target that the spell sword successfully attacks with his weapon (saving throws and spell resistance still apply). Even if the spell normally affects an area or is a ray, it affects only the target. The spell is discharged from the weapon, which can then hold an other spell. A spellsword can channel his spells into only one weapon at a time. Spells channeled into a weapon are lost if not used in 8 hours.

So, if I channel a scorching ray spell, all the rays are discharged in same time on target? Because seems this a bit overpowered - instead of having to make an attack roll for every ray, now he can cause 1d6 + 10 + 12d6 damage (average 47 damage) with just one attack roll for all of them!

This is really right? What's the problem with this class feature? Can I do something to "downpower" this?

Answer 1

The Complete Warrior spellsword is an exceptionally weak class. Entry requires at least one lost spellcasting level, and getting to 4th level requires two more. Lost spellcasting levels are like death to a spellcaster; in most cases it is optimal to never ever not even then lose spellcasting. So to begin, let us keep that in mind.

Furthermore, after the publication of Complete Warrior, similar concepts were produced in Wizard’s Player’s Handbook II with its duskblade, and in Paizo’s Ultimate Magic with its magus. Both of these are base classes, and their versions of Channel Spell (called Arcane Channeling and Spell Combat, respectively) can be used at-will, rather than Channel Spell’s tight per-day limit, and can even be used with a full-attack.

In comparison, the spellsword’s Channel Spell can only be used 3/day at Spellsword 4th, and it requires a move action, which means it will almost certainly preclude a full-attack.

To get 3 rays from scorching ray, the spellsword needs CL 11th. Getting into spellsword and progressing it to 4th causes three lost spellcasting levels, so he’s a minimum of 14th level at that point.

A barbarian at that level would have Strength around 30 while in Rage (18 to start, +6 from Greater Rage, +6 from a belt of giant strength), and could trivially use Power Attack quite safely for substantial damage. Using a two-handed weapon, he’s looking at around 2d6+40 damage for each attack.¹ That matches your 47 damage exactly, but it could happen up to three times in one turn. Unless the spellsword lost even more spellcasting levels to get more, he can only use Channel Spell three times per day.

A spellcaster, meanwhile, could cast scorching ray for 12d6 damage... but it would require only a touch attack, and could happen at range. Touch attacks are dead-easy to make, so a spellcaster should hit with all three. This loses out on the weapon damage, but targeting touch AC is so much easier that the expected damage goes up, not down. But more importantly, a 14th-level spellcaster has much better spells to use. Disintegrate would deal 28d6 damage; that’s an average of 98 damage.

And that’s just pure damage; spellcasters are far more formidable when they don’t deal damage. For example, he could easily haste the barbarian to give him another shot at that 47 damage attack, and it’d hit the druid, the druid’s pet bear, and the rogue, too – easily adding over a hundred damage per round just from the extra attacks all these people get to make.

So yes, you’ve understood the rules of Channel Spell correctly, and no, it’s not powerful at all. Spellsword is considered to be an at-most one-level class (for +1 BAB, +1 level of spellcasting, and 10% ASF reduction), but taking more levels is a mistake, one that even Wizards and Paizo recognized and fixed by publishing duskblade and magus, respectively. To “downpower” the character even more is a bad idea. The class itself already does that too well.

1. ^{Damage derivation: 2d6 (greatsword, average 7) + 1½×15 (Strength, two-handed) + 1 (enhancement) + 5 (collision property, mostly for easy number) + 12 (Power Attaack, taking −6 or −4 penalty in 3.5 or Pathfinder respectively) = 47. Note this uses only two items (+1 collision greatsword and belt of giant strength +6, 54,350 gp out of 150,000 recommended for that level) and one feat (out of five); the number could be much higher with a complete build.}

Answer 2

KRyan's answer is solid and good. But I feel, you misunderstand one thing isn't covered by it. For the sake of pure math, consider an example:
4d6 is 14 damage on average. One attack at +10 bonus potentially dealing 42 damage statistically equals three attacks at the same +10 bonus each potentially dealing 14 damage.
It doesn't matter how many attacks/round you deal in the long run while their attack bonus and average total damage are the same. Yes, sometimes you may hit with one roll for all damage. But if you miss once, you also lose all potential damage for the round.

So even if we won't consider touch attacks and caster levels loss, number of attacks required just won't make some ability less or more powerfull.
So all what Channel Spell actually does in the case of Scourching Ray is trading "ranged touch" type of the attack for additional damage, caused by the weapon.