Feel free to correct me if you think my math is suspect here. All situations obviously assume you are never resisted.
In terms of math, 3T and 1T, 0% penalty are equivalent.
1% crit can be thought of as 1% of the bonus 'possible' damage you can do. So every x crit raises what you'll get out of this. I demonstrate this below are the numbers for comparison at 3%. Plus some hypotheticals.
Archaic Sun Storm 1 target: 985/wave : 2955 total : 5910 possible
Archaic Sun Storm 2 target: 1970/wave : 5910 total : 11820 possible
Archaic: Moon Comet : 2575 total : 5150 crit : 10300 ulti : 20600 prim
MAG 3% crit rate (1/3 penalty | 1/2 penalty)
1T: 05910 * .01 = 059.1 | 05910 * .015 = 88.65
2T: 11820 * .01 = 118.2 | 11820 * .015 = 177.3
3T: 17730 * .01 = 177.3 | 17730 * .015 = 354.6
WIZ 3% crit rate (0 penalty)
1T: 05150 * .03 = 154 + (ult calcs) + (prim calcs)
What does this mean? For every 3% crit, the mage on 1 target can expect an average 59.1 more damage per rain than if he had 0% crit. So 6% would be 118. For every 3% a wizard can expect around 154 + values for ult and prim that we won't be giving out here.
Those are with actual numbers. Now rains are balanced around 2 mobs. You are supposed to be less than optimal on a single target. If you wanted top single target spell DPS be a wizard. Given your numbers and your example as shown...
Now a mage who does 100 waves of damage m.
Mage but with crit 3 will do domage 101m because each wave will have a 1% crit chance.
Damage increase for mage is 101m - 100m ie 1%.
Correct! 100 waves on 1 target with 3% crit only nets you a 1% increase. But wait, rains are meant to be done on 2 targets! What happens in that scenario.
Now a mage who does 100 waves of damage m. Multiple this by 2 targets.
Mage but with crit 3 will do damage 101m x 2 targets because each wave will have a 1% crit chance.
Damage increase for mage is 202m - 200m ie 2%.
2 targets doubled the benefit of the crit. Imagine that. Now as Nwaij said, if anything, it should be reduced from 1/3 to 1/2. Below is 2 targets if we did that. Again at 3% crit chance.
Now a mage who does 100 waves of damage m. Multiple this by 2 targets
Identical mage but with crit 3 will do damage 101.5m x 2 because each wave will have a 1.5% crit chance.
Damage increase for mage is 203m - 200m ie 3%.
Now on 2 targets you get the full benefit. And at no penalty like you are encouraging?
Now a mage who does 100 waves of damage m. Multiple this by 2 targets
Identical mage but with crit 3 will do damage 103m x 2 because each wave will have a 1.5% crit chance.
Damage increase for mage is 206m - 200m ie 6%.
Are you seeing the dilemma now? Now your getting more benefit from the crit then a non raining class.
But wait, while you cast, your pet can be in there attacking independently! And guess what, that damage is nothing to sneeze at. And you can send in some monster summons. Free damage there!
What isn't intended is that pet dying when a mob himself sneezes 5k damage out, that it can't defend against.
If you are still not convinced and have a parser, I can set up an environment with no crit penalty and you can rain to your hearts content until you get some averages you think are accurate. Be sure to have 3 or 4 hours free to do this. Then you can do it again at 1/3 rate. You can see the actual DPS drop that way. Or just follow your own math here.
