Not so. Consider the following situation. A tenth level party facing what ought to be a fairly challenging bad guy (by the numbers)--a Ftr 1/Wiz 6/Eldritch Knight 5 with a few flunkies. The Eldritch Knight has Polymorph, Greater Invisibility, Heroism, Magic Circle against Good, Protection From Law, Mirror Image, Expeditious Retreat, False Life, Overland Flight, Mage Armor, Shield, and Resist Energy: Fire running. He's in the form of an Annis hag wielding a spiked chain with Greater Magic Weapon. The situation sounds like a little bit of a stretch but my 12th level guy had all of those running in his last battle--and with a lesser rod of extend spell, only Shield, Mirror Image, Expeditious Retreat, Polymorph, and Greater Invisibility last less than three hours. Even then, only Greater Invisibility lasts less than ten minutes.
The party wizard isn't an unusual sort. He's got See Invisibility running and has glitterdust, a scorching ray, acid arrow, fireball, lightning bolt, Dispel Magic, Slow, Phantasmal Killer, Fire Shield, a quickened magic missile, and an empowered fireball prepared. He's got a 20 int (starting 16+2 levels, +2 headband) so his DC is 15+level.
The BBEG is running on 28 point buy (not that it matters a whole lot with polymorph and his saves are +12/+10/+12. If the wizard tries a dispel magic, since they've equal caster levels, odds are good that he'll strip half of those protections and buffs away (and stripping the false life will do an average of 16 hit points effective damage) leaving the BBEG in poor shape to face the party's enlarged fighter. OTOH, if he tosses a phantasmal Killer at the BBEG, he's only got a 30% chance of doing anything and a 9% chance of killing him. If he tosses the slow, he's got a 25% chance of effecting the BBEG. Scorching Ray? Almost no chance. Empowered Fireball? An average of 12 points of damage. Lightning bolt? An average of 22 points of damage.
I'd say that smart money is on either the dispel magic or the glitterdust in this situation--with dispel magic edging out glitterdust since knowing where the BBEG is doesn't make him THAT much less dangerous to the rest of the party.
A less extreme situation:
An 8th level party vs. a 10th level evil cleric and a few minions. The cleric started out with Longstrider, Magic Circle Against Good, Shield of Faith, and Barkskin (he's a plant domain cleric) running. Somehow he got wind of the combat (could it be that he actually has an alarm system in his lair? Or maybe he just heard the battle going on outside). Either way, he put up Fly, Divine Power and Righteous Might before stepping out to smash the PCs.
The 8th level Cleric in the party has Sound Burst, Hold Person, Blindness/Deafness, Inflict Serious Wounds, Dispel Magic, Searing Light, and Holy Smite ready for offense. He's a wise cleric and has a 20 wis (16+2 level +2 item).
Since the evil cleric's saves are almost certain to be +10/+4/+12 (or better), the only good choices are Searing Light and Dispel Magic. Searing Light will do an average of 18 points of damage--if it hits (even though it's a touch attack, our cleric's low dex means that's not guaranteed--his ranged touch is only +6 and it's going against a touch AC of 13 or 14 (with a -4 penalty if he's firing into melee so he's got a 50-70% chance of hitting--good but not certain)). The targetted Dispel Magic will probably get 2 or 3 of the villain's buffs--dropping Divine Power is as good as dealing 8 points of damage and if righteous might would only effect two blows the whole combat, dropping it deals an effective ten points of damage, not to mention decreasing the villain's offensive capability. I'd say that smart clerics use dispel magic in this situation too. It's far more likely to work (99% chance of dispelling at least one buff and a 40% chance of dispelling any one particular buff) than the Hold Person (20%) or the Blindness/Deafness (35% and the cleric has a 60% chance of simply dispelling it on the following round) or Holy Smite (30% chance of full damage and blinding the cleric for one round). Say the villain put up Spell Resistance and the case for a targetted Dispel Magic is sealed.
And Dispel Magic is also useful against battlefield altering magics too. A wall of fire? No problem. Enemy covering his retreat with a fog cloud? Dispel it. Dropped a Mind Fog on the group? Dispel it. Trapped you in a resilient sphere? Dispel it. Enemy cast Cloudkill then sealed you in the cave using a wall of force? Dispel the cloudkill. Enemy wizard polymorphed your wizard into a toad in the surprise round. Dispel the polymorph and (effectively) summon a level 8+ wizard for the rest of the encounter with a 3rd level spell.
Dispel Magic can be a darn good tactic.
FrankTrollman said:
This is a seriously crappy tactic. Against any opponent that this has even a 50% chance of working against, you could just send a death spell after them and have about a 50% chance of killing them outright.
Dispel Magic is not more likely to work than is a Save or Die spell - and when it works, your opponent isn't dead. If you are ever in a posiiton to dispel someone's Polymorph there are automatically better things you could be doing with your time.
Dispel Magic is only to undo curses and advance the plot. Sometimes you need that spell, but never as an offensive weapon.
-Frank
