A while ago, I asked this question in the EJ Simple Questions/Simple Answers thread:
Is there a noticeable difference in DPS between using a priority system (I’m currently 2h frost specced, 20/51, so something like: Refresh FF > OB > weaving FS between strikes/when KM procs > HB on Rime procs > BS) and sticking to a strict rotation?
First, some definitions:
A “strict rotation” is theorycrafting up a sequence of abilities that, when mashed in order, make for good DPS. Note that this is not an excuse to use a /castsequence macro, since if you miss/have to move away in the middle of the macro, you are basically screwed. Here’s an example, from a previous post: IT – PS – OB – BS – BS / OB – IT – IT – OB (weaving FS between attacks). The idea is that if you use these abilities, in the set order, you’ll do excellent damage. The disadvantage of a rotation is that it’s a bit boring (to me) and can lead to some tunnel vision, being focused solely on hitting the correct buttons in the right order rather than on what’s going on around you.
A “priority system” is fairly self-explanatory. Give all possible abilities a priority, and use them in that order. Here’s an example, with 1 being the highest priority and going down from there (for a Frost Death Knight on a single-target fight).
- Frost Fever (applied either through Icy Touch, Pestilence or Howling Blast)
- Frost Strike (if RP would go over 130 or you have a Killing Machine proc or all your runes are on cooldown)
- Blood Plague (ignore this if you’re running a one-disease rotation, such as with the HB glyph)
- Howling Blast (if you have a Rime proc)
- Blood Strike
The advantage of using a priority system is that it lets you react to anything that comes up with more ease than using a strict rotation. This is because when something interrupts your DPSing, when you get back to it you just evaluate what your next attack should be based on the priority system. The downside of this method is that it’s more difficult; you have to do a lot more quick thinking because, especially for frost, procs are random and can change what you want to do with your next GCD.
Personally, I find the concept of a set DPS rotation very hard to follow. I get distracted by moving out of the fire and any other element of a fight that pulls me off the boss or directs me towards killing adds. If you currently use neither of these systems (though even if you think you don’t, you probably have some kind of unconscious priority system), I urge you to try both and see which one better suits your playing/DPSing style. Note that Frost and Unholy rotations are more subject to randomness, due to the use of the Scourge Strike glyph and Frost’s various procs, when compared to Blood, whose only proc (Sudden Death) was changed to a free DC in 3.1.