Shadow Priest DPS Rotation

[Chamomile]

It seems that there are a few more cropping up recently and maybe sharing the rotation I use would be helpful.

My personal rotation is as follows: (Please note that depending on your haste level, this may not work quite right.)

Vampiric Touch
Shadow Word: Pain
Devouring Plague
Mind Blast
Shadow Word: Death
Mind Flay
Mind Flay
Mind Blash
Mind Flay
Vampiric Touch
Shadow Word: Death
Mind Flay
Mind Blast
Mind Flay
Archangel
Devouring Plague
...then basically refresh the two dots as they wear off, MB and SW:D as they become available, Archangel after five Mind Flays and MF all other times.

An alternately suggested rotation that I haven't tried out myself suggests leading with SW:P, to DP, VT, SW:D, MB, MFx3, SW:D, MB, VT, MFx2, DP, Archangel, then again refresh and use on cool down as above.

Unless the fight goes extremely long, you shouldn't run out of mana. Feel free to lead with shadowfiend or to save it if fight mechanics will cause trouble with your mana.

My spec and glyphs can be found here. This seems to be the recommended build.

For items, you want to prioritize the stats as follows:
Int -> SP -> Haste -> Crit -> Mastery -> Spirit -> Hit

Note that spirit is one for one the same as hit. Your hit cap is 1742 and you will want to be as close to that number without going below it. So technically Spirit and Hit are both rather high on your priority list, but once you hit that cap, it's near useless afterward.

I have two macros that make it easier to recast MF without clipping it. Since the buttons you will likely be hitting are the most are MB and MF, I've replaced those two spells as follows:

MB:
#showtooltip Mind Blast
/cast [nochanneling] Mind Blast ;

MF:
#showtooltip Mind Flay
/cast [nochanneling:Mind Flay] Mind Flay ;

That way if you're already channeling a spell, you can't cast MB and if you're already channeling MF, you can't recast it and miss a tick or two of damage.

Mind Sear got nerfed into the ground, so your AoE options are pretty terrible. In most cases, you're better off just continuing to single-target dps. If there's a lot of trash, just tab and mind spike. In my experience, that's all MS is good for since killing your dots isn't worth the increased crit chance on the next MB.