Guide to Moonkin Idols

Edit: As I continued to think about this I decided to post my argument and a couple of suggestions for this idol on the WoW forums. You can find the post here.

I've been getting a lot of questions lately about Moonkin idols with [Idol of the Crying Wind] becoming available from Ulduar. In this post I will do the math for all three WotLK idols and show you which idol is best in each rotation. As always, if you don't want to see all of the math please feel free to skip to the bottom for the TL:DR version.

Assumptions:
1. I am using my talent build. It is fairly standard and I don't think there are any variations that would significantly change the out come of my math. I did run the numbers with 5/5 in Genesis and the impact was minimal.

2. Fully Raid buffed, my Hypothetical Moonkin has 2900 Spell Power, 40% Crit Chance, 29.77% Haste, and is fully hit capped.

3. I am also assuming that the [Glyph of Insect Swarm] is in use and that the 2T7 set bonus is being used.

About Idols:
I want to say a little bit about how Idols work. It is a little confusing and caused me to make an error in my math. The Wrath Idol increases "Damage Dealt," therefore it is not affected by the spell coefficent. The SF Idol says it increases Spell Power, but is not affected by Wrath of Cenarius. So it acts as if it is just an increase to base damage. The IS Idol says it increases Spell Power and is modified by the 1.2 spell coefficent that IS has.

The Math:
First lets look at the [Idol of the Shooting Star].

Here is Starfire's DPS without the Idol.

NG Uptime with SF = 1-(1-0.4-0.03)² = 67.51%
SF Avg Cast Time = (3/(1+0.2977))*(1-0.6751)+(3/((1+0.2977)*1.2))*0.6751 = 2.0516 Seconds
Avg SF Non-Crit = (1120 + (2900 * 1.2))*(1.1*1.04*1.03) = 5420
Avg SF Crit = (1120 + (2900 * 1.2))*(1.1*1.04*1.03)*2.09 = 11328

Avg SF DPS w/o Idol = ((5615*(1-0.43))+(11735*0.43))/2.0516 = 3880 DPS

With the Idol math looks like this:

Avg SF Non-Crit = (1285 + (2900 * 1.2))*(1.1*1.04*1.03) = 5615
Avg SF Crit = (1285 + (2900 * 1.2))*(1.1*1.04*1.03)*2.09 = 11735

Avg SF DPS w/ Idol = ((5615*(1-0.43))+(11735*0.43))/2.0516 = 4019 DPS

So by equipping the SF Idol your increasing your Starfire's damage by 286 per cast or by 139 DPS.

The math for the [Idol of Steadfast Renewal] is very similar to the above math.

Without the idol it looks like this:

NG Uptime with SF = 1-(1-0.4)3 = 78.40%
W w/o NG Cast Time = (1.5/(1+0.2977)) = 1.1559 Seconds
W w NG Cast Time = (1.5/((1+0.2977)*1.2)) = 0.9632, Therefore 1 second since 0.9632 less than 1.
W Avg Cast Time = (1.1559*(1-0.7840)) + 0.7840 = 1.0337 seconds

Avg W Non-Crit = (588 + (2900 * 0.6714))*(1.13*1.04*1.03) = 3069
Avg W Crit = (588 + (2900 * 0.6714))*(1.13*1.04*1.03)*2.09 = 6413

Avg W DPS = ((3153*(1-0.40))+(6590*0.40))/1.0337 = 4263 DPS

Now with the Idol, Wrath's DPS looks like this:

Avg W Non-Crit = (658 + (2900 * 0.6714))*(1.13*1.04*1.03) = 3153
Avg W Crit = (658 + (2900 * 0.6714))*(1.13*1.04*1.03)*2.09 = 6590

Avg W DPS = ((3153*(1-0.40))+(6590*0.40))/1.0337 = 4380 DPS

So by equipping the Wrath Idol your increasing your Wrath's damage by 122 per cast or by 117 DPS.

Now lets look at the new idol, [Idol of the Crying Wind].

Insect Swarms math is a little bit easier. It currently looks like this without the idol:

IS Damage = (((1290 + (2900 * 1.2)) *(1.4*1.04*1.03))*(7/6))/14 = 596 DPS

Now, If you add the new idol in it looks like this:

IS Damage = (((1290 + (3274 * 1.2)) *(1.4*1.04*1.03))*(7/6))/14 = 652 DPS

Therefore when equipping the IS Idol, your increasing your IS damage by 785 damage, but that is over 14 seconds. In terms of DPS its only an increase of 56 DPS.

TL:DR Version:
In terms of a single spell cast the [Idol of the Crying Wind] looks decent because it increases your Insect Swarm damage by almost 8%. However, this ignores one very important problem. Since Insect Swarm is a DoT your only going to be casting it once every 14 seconds at most.

What the [Idol of the Shooting Star] and [Idol of Steadfast Renewal] lack in power is made up for by the fact that Starfire and Wrath can be cast multiple times over 14 seconds. You can see this difference by comparing the Idols DPS numbers. The DPS on the nuking idols are about 3 times larger then the DPS increase from the IS idol.

As long as your cast 3 or more Starfires per 14 seconds or 6 or more Wraths per 14 seconds on average, then the[Idol of the Crying Wind] is not for you. No moonkin should be below that level. The only time I would use the IS idol right now is for Flame Leviathan because it has a higher item level then the other idols. A commenter pointed out something I had forgotten, the "ranged" slot isn't used in the FL calculation so this idol isn't even good for that. However, I do want to say one thing. I still think all moonkin should pick it up if they can get it for free or very little DKP. You never know if Blizzard will buff it after they realize that no one is using it.

When deciding between the SF idol or the Wrath idol, the choice is pretty easy. Technically the SF idol is a little bit better, but the difference is pretty small. Therefore, if your using a Lunar Rotation, then [Idol of the Shooting Star] is the right idol for you. If your using a Solar Rotation, then [Idol of Steadfast Renewal] is the better idol.

One last thing, none of the TBC idols are worth equipping at level 80. Both the SF idol and Wrath idol are now purchaseable with Emblems and they blow anything the TBC idols offer out of the water.