How does the ring of mystic fire interact with scorching ray?

Question

In my D&D 3.5 campaign, one PC just got a ring of mystic fire, and I'm trying to figure out how the ring works with the spell scorching ray.

The Magical Item Compendium says

A ring of mystic fire provides a boost to your fire-based spells. When casting spells with the fire descriptor, you gain a +1 competence bonus to caster level. This is a continuous effect and requires no activation. The ring has 3 charges, renewed daily at dawn. Spending 1 or more charges grants a bonus to the amount of damage you deal with the next fire spell you cast before the end of your turn. (If the spell doesn't normally deal fire damage, this expenditure has no effect).

• 1 charge: +2d6 fire damage
• 2 charges: +3d6 fire damage
• 3 charges: +4d6 fire damage

My player intends to use all 3 charges for +4d6 fire damage with the scorching ray spell, which says

You blast your enemies with fiery rays. You may fire one ray, plus one additional ray for every four levels beyond 3rd (to a maximum of three rays at 11th level). Each ray requires a ranged touch attack to hit and deals 4d6 points of fire damage.

The rays may be fired at the same or different targets, but all bolts must be aimed at targets within 30 feet of each other and fired simultaneously.

My question is this: Does the ring of mystic fire grant the character a +4d6 fire damage per ray? I'm inclined to rule that the ring does add its damage to each ray, but that risks making the spell overpowered, even though it is only once per day. And, even if overpowered, I prefer to rule in favor of what makes sense.

Answer 1

The ring of mystic fire only affects the upcoming spell once

The ring of mystic fire (Magic Item Compendium 125) (7,500 gp; 0 lbs.) does, indeed, grant "a bonus to the amount of damage you deal with the next fire spell you cast before the end of your turn," but the ring only grants that bonus once. Each ray of a scorching ray spell isn't the spell; instead, the whole spell creates multiple rays. The ring improves the spell's damage only once by a maximum of +4d6 no matter how many effects result from the ring-modified spell.

(Ruling that each ray of the scorching ray spell benefits from the ring multiplies the power of the ring by the number of rays—with rather extreme consequences at low levels, especially given that the ring increases also the wearer's caster level for fire spells!)

Although the DM has several options available to adjudicate the ring's effect—allowing the player to distribute the total number of extra dice damage the ring grants among the rays before (or even after) the rays're launched, for instance—, this DM would keep things simple and have the player add the extra damage to his PC's first ray in a volley from the spell scorching ray, in much the same way that precision damage applies to the first attack in a similar volley (Rules Compendium 42). (In fact, I have a fire wizard in a current campaign who's eyeing this very item, and that's how I'm ruling it works.)

Hence, for example, under such a ruling, a level 6 caster wearing a ring of mystic fire can take a swift action to spend 3 of the ring's charges. Then the caster can cast scorching ray, creating 2 rays (because of the increase in caster level granted by the ring) and making 2 ranged touch attacks. If the first ray hits, it deals 8d6 points of fire damage. If the second ray hits, it deals 4d6 points of fire damage.

Answer 2

Yes

If you cast a Fireball for 5d6 and used that ring, every target hit by the fireball would take 10d6 damage (+1d6 from the level up, +4d6 from the effect).

The effect boosts the damage the spell does. The ring does not state "once". So when you evaluate damage on the next fire spell you cast, you simply add +4d6.

This is a reasonably strong combo, but it is only damage. If your 3.5e wizards are dealing damage, they aren't as strong as they could be.

An alternative explaination would be that the damage bonus applies the first time the spell deals fire damage to any target. So a fireball would deal 6d6 damage, but the first thing damaged would take +4d6 damage. This +4d6 damage would not be subject to saving throws. Similarly, the rays would shoot out, and the first target hit (and hence damaged) would take +4d6 damage. I don't buy it, there are too many choices to make in how exactly this works.

The ability says the next fire spell deals +4d6 damage. You should take it at its word, at least initially, and check if it breaks the game.

For a sanity check, we'll see how badly this breaks the game. A level 10 wizard using it hits for 3 rays at 8d6 each, or 84 total damage (touch attack).

Picking 3 random CR 10 creatures, none of them die even if everything hits. They have over 100 HP.

It isn't one-shotting an even-CR creature. A wizard could do better: winning a fight against an even-CR creature is what a good spell does. So this isn't a huge balance issue in general. It could be in your party specifically.

We should also look at how it interact with other fire spells: it is also efficient with flaming sphere (and a way to make them not run away), at 2d6+4d6 damage per round (reflex negates), or flame arrows with archers to help (the arrows deal +5d6 damage each), or fire trap (where you pre-cast it when not adventuring for 1d4+level+4d6 damage), fire shield (where it applies to each time it deals damage 5d6+level), or wall of fire with solid fog (or other means to trap foes) for more than one round.

For fast burst, a meteor swarm isn't bad (6d6+4d6 all times 4, for 40d6 damage).

For more fun, Elven Spell Lore on a magic missile to fire damage. Each one deals 1d4+1+4d6 fire damage, and at level 10 you get 6 of them. 105 damage, no save, no to-hit roll.

And even with that attempt at breaking it, it still isn't the best use of an action.

Answer 3

No

... grants a bonus to the amount of damage you deal with the next fire spell you cast ...

The damage is to the spell (singular); he would have 4d6 that he could apply across the rays that he has.

Answer 4

The simplest answer is actually that it does +xd6 per target per spell.

So, if you boost it to +4d6, it will deal the additional damage to every target you hit with a Scorching Ray, just like a Fireball would. If you hit the same target with all rays, it only takes the +4d6 once, just like a fireball.

This removes the difference in application between rays/magic missile effects and AoE's for damage boosts, and makes them slightly more effective against multiple opponents, while not overpowering them with additional damage.