The task of giving rogues three unique specs is incredibly difficult. Our class design doesn't allow for much flexibility in our mechanics. Assassination, combat, and subtlety all rely on the same energy bar and the same combo points to get the job done. The cyclical rotation of generators and finishers is always going to make up the core of our button presses.
Rogue spec diversity is maintained by three main tenets: differing finishers, interesting cooldowns, and a unique generator mechanic. All rogues will be using Shadow Blades as often as possible and Feint to reduce their damage taken. The utility abilities of the class have been consolidated, and the variance in how we deal our damage is what's left to separate each spec.
Mastery is futile
Our mastery effects do nothing to create a niche for a particular spec. Assassination rogues, via Potent Poisons, will deal more poison damage than combat rogues. Combat rogues, via Main Gauche, will deal more physical damage than assassination rogues. Subtlety rogues, via Executioner, will have harder-hitting finishers than either of the other two specs. Unfortunately, none of these mastery effects are interesting or actually influence our gameplay.
I'm more than willing to spar with you about how the theme of each spec is pointless in the grand scheme of things. If there were heavily-armored bosses in the game, assassination would have the clear upper ground on its rivals. If the developers designed every battle to feature not one, but two targets, combat rogues form the core of every raid group. If our encounters only lasted for 10 seconds, the terrible fury of subtlety would be unbeatable. Unfortunately, there aren't, they won't, and they don't.
The mechanical view
If we divorce ability names and spec-specific details, we can get a better idea of what it actually feels like to play a given rogue spec. We're all players that are pushing buttons on our keyboards, and the actual actions we take are going to reflect on our experience with the class.
I took a few parses from World of Logs for all three specs and broke down their actual actions to get an idea of how each class feels. Assassination was clearly the slowest spec, with about 0.5 actions-per-second overall. Combat and subtlety rogues, on the other hand, were unloading 0.65 aps, which is a 30% increase. The difference is noticeable when you switch to or from an assassination build. Considering our absolute maximum of 1 aps (based on our global cooldown), you can see that assassination rogues spend 50% of their time idling.
Subtlety is gracefully complex
Subtlety rogues had the highest number of unique abilities used, due to their dual generators, complex finisher suite, and multipart cooldowns. Their abilities were fueled by 8.8 bonus energy per second, caused by Relentless Strikes and Energetic Recovery. Backstab leads the pack with 43% of total actions, while Hemorrhage comes in at 13%. Generators make up about 56% of their overall repertoire, which was by far the lowest of the three builds.
Subtlety rogues had to balance their time between Slice and Dice, Rupture, and Eviscerate. With no ability to refresh SnD like assassination or the luxury of ignoring Rupture like combat, subtlety rogues have to juggle all three finishers. They spend 33% of their actions on finishers, which was the highest of the three specs. It makes sense for sub rogues to use a lot of finishers, due to their Executioner mastery effect.
What's more interesting is how much Shadow Dance and Ambush contributed to subtlety's mechanics. With a handful of Shadow Dances and a total of 16 Ambushes, subtlety rogues spent more time pushing cooldown-specific actions than combat and assassination rogues combined. Shadow Dance forces sub rogues to play differently, while Vendetta and Adrenaline Rush don't change anything at all. Shadow Dance should be a model for all rogue cooldowns.
Combat is stunningly simple
Combat rogues are a one-button wonder. They're usually able to ignore Rupture, which gives them a very simple two-finisher rotation. If it weren't for the added complexity of watching the Revealing Strike duration, combat rogues would be exactly as they were in Cataclysm. Fueled by a healthy 8.3 bonus energy per second via Combat Potency and Relentless Strikes, combat was able to keep pace with subtlety rogues in terms of actions-per-second.
Combat rogues push Sinister Strike a lot. In fact, Sinister Strike makes up 67% of their actions, a full 2/3 of their button presses. No other ability for any other rogue spec comes anywhere close. If you're playing combat, make sure you rest your SS-mashing finger between encounters. When you add in a few Revealing Strikes for another 10% of the total, combat rogues are using 77% of their actions on generators. This level of simplicity is why combat rogues are the easiest spec to learn.
In fact, with their finishers making up just under 18% of their overall actions, combat rogues spend nearly all of their time mashing generators. If it weren't for the occasional Killing Spree, combat rogues would be down to a 5-button class once again. Adrenaline Rush does nothing to assuage the simplicity of the spec, but rather enforces it. The best thing for a combat rogue is to pop AR and Shadow Blades while spamming Sinister Strike with reckless abandon. Combat has the least diverse set of abilities, but it's high actions-per-second can make it tolerable.
Assassination is just slow
Comparing my parses, assassination rogues performed significantly fewer actions than their subtlety and combat counterparts. You can immediately see that they generate less energy than the other specs, as Venomous Wounds and Relentless Strikes combined for barely 6.7 bonus energy per second, which is 25% lower than combat's bonus energy (not counting Vitality).
Assassination rogues focus on Mutilate for the first portion of an encounter, and then they switch to Dispatch once a boss' life is brought low. While they are two different abilities on paper, they're completely interchangeable and there's no actual decision-making that goes into choosing one or the other. The combo of Mutilate and Dispatch make up 60% of assassination's actions, which is similar to subtlety but far lower than combat's lopsided assault.
With Envenom refreshing Slice and Dice automatically, assassination rogues only really need to watch their Rupture timer. It's actually quite similar to combat's rotation, although with a bit more that can go wrong. Assassination's finisher percentage sits around 27%, which is quite reasonable and fits between combat and subtlety nicely.
Vendetta is the game's most boring ability. You activate it, and then do everything exactly as you have been the whole time. In fact, with no other spec-specific cooldown available, assassination would be incredibly boring if it weren't for Blindside. Blindside is the only breath of fresh air for the spec. With an average of 10% of an assassination rogue's abilities being free Blindside procs, they're using it as often as a subtlety rogue uses Ambush. The difference is that Ambush deals massive damage and it requires a great deal of preparation to execute a Shadow Dance properly. With every rogue picking up Anticipation, you can spam your Blindside button without a care in the world.
Assassination's sin is being both slow and boring. You're earning at least 25% less energy, executing 30% fewer actions, and you have no ability that requires any thought or foresight. Vendetta and Blindside are completely wasted buttons. Procs should force rogues to make a decision and cooldowns should dynamically affect our play. Vendetta is just as bad as the old Hunger for Blood and Blindside's proc could be converted to random damage and nobody would notice. Unfortunately for us, assassination is also the spec dealing the most damage in raid environments. That's irony.
Sneak in every Wednesday for our Molten Front ganking guide, a deep-dive into the world of playing a subtlety rogue -- and of course, all the basics in our guide to the latest rogue gear.