IcyCool said:
It was originally in Complete Arcane (as is the most recent ruling for sneak attack on spells).
Right. The Warlock, Eldritch Blast, Eldritch Chain, and the rules for weaponlike spells are all in the same book.
So it's fairly clear that the rule about Multiple Hits (found in Complete Arcane) applies to Eldritch Chain, a spell-like ability that allows Multiple Hits (found in Complete Arcane).
I believe it first cropped up in Tome and Blood, which was the 3.0 wizard/sorceror supplement.
Yup.
There's no such requirement in the 3.5 PHB description of the ability.
If a rogue can catch an opponent when he is unable to defend himself effectively from her attack, she can strike a vital spot for extra damage. The rogue’s attack deals extra damage any time her target would be denied a Dexterity bonus to AC (whether the target actually has a Dexterity bonus or not), or when the rogue flanks her target. This extra damage is 1d6 at 1st level, and it increases by 1d6 every two rogue levels thereafter. Should the rogue score a critical hit with a sneak attack, this extra damage is not multiplied.
Ranged attacks can count as sneak attacks only if the target is within 30 feet.
With a sap (blackjack) or an unarmed strike, a rogue can make a sneak attack that deals nonlethal damage instead of lethal damage. She cannot use a weapon that deals lethal damage to deal nonlethal damage in a sneak attack, not even with the usual –4 penalty.
A rogue can sneak attack only living creatures with discernible anatomies—undead, constructs, oozes, plants, and incorporeal creatures lack vital areas to attack. Any creature that is immune to critical hits is not vulnerable to sneak attacks. The rogue must be able to see the target well enough to pick out a vital spot and must be able to reach such a spot. A rogue cannot sneak attack while striking a creature with concealment or striking the limbs of a creature whose vitals are beyond reach.
1. Are you attacking?
2. Are you flanking, or is the opponent denied Dex bonus?
3. If it's a ranged attack, is the opponent within 30 feet?
4. Is the target immune to sneak attacks, or concealed, or with vitals beyond reach?
Once you've answered those four questions, you know whether or not the Core Rules say you're eligible to sneak attack.
If you include rules from Complete Arcane, then there's a fifth question:
5. If the attack is a spell, is it a spell that requires an attack roll and deals damage?
But if you refuse to include rules from Complete Arcane, this question is not pertinent, and so Magic Missile can satisfy all the requirements. In addition, since the Multiple Hits rule also appears in CA, refusal to include such rules would mean that Magic Missile could potentially add sneak attack damage five times.
My recommendation? Include the rule from CA.
-Hyp.