changing damage type of a spell?

[Deaxsa]

how does one do this? (for instance, if i wanted to make a fireball that did cold, acid, or heck, even force damage)

[Talderas]

Energy Substitution Metamagic Feat.

It's from Complete Arcane. You need five ranks of Knowledge Arcana and another metamagic feat to take it. Each time you take it you choose fire, cold, electricity, or acid and you can change any spell with an energy descriptor into the type you chose. There is no increase in spell's level for altering the energy type.

So you can take Energy Substitution [Acid] and caster Fireball with acid damage instead of fire damage as a 3rd level spell.

[Wookie-ranger]

Energy Substitution Metamagic Feat.

Agreed. In addition the MM feat "Lord of Utter-cold" Makes a spell 1/2 cold and 1/2 negative energy damage.
A very neat feat for a necromancer, as Skeletons are immune to cold and get healed by negative energy.

[The Viscount]

Through the use of the Snowcasting feat from Frostburn, you can give any spell the cold descriptor, making it a candidate for Energy Substitution.

[Deaxsa]

Through the use of the Snowcasting feat from Frostburn, you can give any spell the cold descriptor, making it a candidate for Energy Substitution.

oh, that's actually really really cool. (or not) (pun intended)

thank you everyone

[Jane_Smith]

Well, its up to your dm, you could take energy substitution, but if you check the dmg, it says players can design their own spells. Making a variant of fireball called snowball as a new spell that does the exact same things but cold damage is easily balanced, but it would be up to the dm. I don't see any reason why he would say no myself, but meh.

[Krobar]

Well, its up to your dm, you could take energy substitution, but if you check the dmg, it says players can design their own spells. Making a variant of fireball called snowball as a new spell that does the exact same things but cold damage is easily balanced, but it would be up to the dm. I don't see any reason why he would say no myself, but meh.

You get more bang for your buck (or gold piece) with energy substitution. If you have fireball memorized, with energy substitution it could be fireball or snowball, depending on what you need at the time of casting.

But if you write a separate spell, to have both available you need to memorize both. Or know both.

Not to mention all the other spells you might know that could have their energy descriptor swapped.

[Deaxsa]

Well, its up to your dm, you could take energy substitution, but if you check the dmg, it says players can design their own spells. Making a variant of fireball called snowball as a new spell that does the exact same things but cold damage is easily balanced, but it would be up to the dm. I don't see any reason why he would say no myself, but meh.

I am the DM, just trying to help one of my players. besides, wouldn't that mean he has to spend resources researching the spell? what page of the DMG is that on, i can't find it on the SRD. also, the energy sub route would probably be better for a sorcerer, seeing as he would only need to know different shapes of spells (a ray, a cone, a ranged AOE like fireball, etc) and the feat heighten spell. (which he is not, but this is more an exercise in theorycraft now anyways)

edit: and then said sorcerer could take the metamagic ACF where you lose a familiar but also lose the increased casting time of metamagic spells.

[KillianHawkeye]

You get more bang for your buck (or gold piece) with energy substitution. If you have fireball memorized, with energy substitution it could be fireball or snowball, depending on what you need at the time of casting.

This is incorrect. A Wizard (or other prepared spellcaster) must decide at the beginning of the day whether or not to apply metamagic feats to any of his spells. He cannot prepare a Fireball and later decide to swap its energy type to cold.

[Icewraith]

I believe archmage mastery of elements may be what you're looking for (technically). The feat tax is onerous (2 spell focuses and skill focus:spellcraft IIRC), and you can't do it until fairly high level, but you get fire, cold, electricity, acid and SONIC. It permanently costs an upper mid-level spell slot, but I believe it does allow for on-the-fly element modification for wizards and doesn't adjust the level of the spell.

Also I'm not aware of any way to get [force]. Archmage is the most thorough, though probably not the most optimal way to change damage types depending on what you're going for. You can probably skate by with snowcasting, acid, and lightning if you want to cover your bases fairly well with energy substitution, for a total of four feats. Fire and cold are the most common immunities by far, sonic is usually the most useful and isn't eligible for energy substitution.

To give you an idea of how good sonic damage is compared to the others, most psionics and spells written after core reduce the number or size of damage die if dealing sonic damage. It's almost as good as force damage (and again, you'll notice most force descriptor damage spells deal less total damage than comparable spells of the same level on a per round basis).

Also, you can pick up an equivalent to Reach Spell with another level of archmage, and an additional level you could grab mastery of shaping, which lets you poke holes in your area spells so you don't blast your friends (again, at no spell level adjustment, and again there is a metamagic feat that does most of the same thing but increases the spell level).

Most of these can be done individually at lower level with metamagic feats, but Archmage is more versatile and if you're taking three levels for all those abilities, may be a better package deal. Since you're blasting anyways, spell focus: evocation and conjuration will increase your save DCs for the majority of element-based spells so the feats aren't completely wasted. The only real downer is you have to be 13th or 14th level IIRC to even think about this class.

Most of the board is in agreement that a wizard generally has better things to do than blast, but if you want to blast, and you really want these specific abilities, then consider Archmage.

Edit:

Depending on how feat heavy you want to go, I believe searing spell changes damage type to fire (not so useful) and deals half damage to fire-immune creatures (somewhat useful).

There's another metamagic feat that eliminates the increased casting time for metamagic and spontaneous casters, requires 9th level I believe. Rapid metamagic?