So a huge cornerstone of this build is actually a very simple (triplicate of) concept(s).
- Build Combo Points FAST, using the least amount of Energy (and therefore TIME) needed to do so.
- Use more Finishers Per Minute (FPM?) than other builds can offer or manage.
- Don’t get caught or stuck needing to rely on a SINGLE tactic or strategy for victory to the exclusion of all else.
The cheapest (repeatable) attack, in terms of Energy, that can build Combo Points is Hemorrhage. Everything else you can do is 40+ Energy to attack for +1 Combo Point when out of Stealth. Hemorrhage is 35 Energy. That’s HUGE, even if it doesn’t look like it at first. In a lot of situations (a lot!), that’s the difference between being able to use another Hemorrhage or a Finisher right NOW, or needing to wait another 2 seconds for another +20 Energy tick to arrive. Hemorrhage ALONE will accelerate your Build To Finish cycles by an entire Energy recovery tick (or 2!) relative to what you’d be doing with (Improved) Sinister Strike (let alone trying to Backstab for 60 Energy!). The tempo change is something that you have to experience directly in order to be able to appreciate because there’s a sort of “granularity” to the timing of Energy recovery ticks. You’re just simply more efficient at generating Combo Points to use with your Finishers when you have Hemorrhage. Because it takes less resources to do, and is therefore more efficient, you complete each Build To Finish cycle more quickly than the alternatives. It really is that simple.
Also, Hemorrhage allows you to “front stab” as a Rogue (so to speak), rather than needing to rely on Backstab (with Daggers) for high damage. Being allowed to use the same attack from any position relative to your target can make life a LOT less frustrating. Think of the difference between Hemorrhage and Backstab just in sheer Energy cost terms.
35 vs 60 Energy per use means that Backstab costs 60/35=1.714x more Energy to cast Backstab than it costs to cast Hemorrhage … but Backstab does only 1.5x weapon damage plus a little bit more (+15 to +225 depending on Backstab rank) if you’re not counting the Hemorrhage debuff (that adds +3 to +7 Physical damage per hit for 30 charges or 15s). So you can cast Backstab once, for 60 Energy and +1 Combo Point, but only from behind your Target … or your can cast Hemorrhage twice, for 70 Energy and +2 Combo Points, with no restrictions on your location relative to your target. So for only +10 Energy more, you can do roughly the same amount of damage with Hemorrhage as you can with Backstab, from any direction (not just from behind), while also earning +1 Combo Point in the process. In other words … win-win-win … for relying on Hemorrhage over Backstab as a Dagger Rogue.
To buttress that effort of building Combo Points as quickly (and efficiently) as possible using as little Energy as possible, I’ve invested in Ghostly Strike (125% weapon damage for 40 Energy, +15% Dodge for 7s on a 20s cooldown) and Setup (for a chance for a free Combo Point when you Dodge a melee attack) along with Ruthlessness (for a chance for a free Combo Point after using a Finisher). And supplemental to all of those talents, I’ve even got Lightning Reflexes (additional Dodge chance) to maximize the opportunities for free Combo Points yielded by Setup (especially after use of Ghostly Strike). In combination, all of these talents offer a wealth of opportunities for free Combo Points that don’t require the consumption of Energy to generate (so long as you’re being attacked by melee). That means that my Build To Finish tempo will simply be faster (in PvE), because it will cost less Energy to build up those Combo Points in preparation for use in a Finisher. I’m not Global Cooldown CASTING more (which costs Energy), I simply need to Dodge more in order to add on “free” Combo Points.
Specifically, opening from Stealth will usually involve use of either Ambush, Garrote or Cheap Shot … which costs 50 (Garrote) or 60 (Ambush or Cheap Shot) Energy to cast. This can then be immediately followed by Ghostly Strike for 40 Energy so as to self-buff your own Dodge chances by +15% during the “most dangerous” portion of the engagement after breaking Stealth. Total Energy cost for this opening is 90 or 100 Energy, which can be easily managed by any Rogue when starting from 100 Energy prior to the opening attack from Stealth (and only consumes +5 more Energy when using Ghostly Strike after opening from Stealth instead of Hemorrhage). The next attack to cast will usually be Hemorrhage (after Ghostly Strike), which costs 35 Energy and will require 2 Energy recovery ticks to complete before it can be used, which can take up to 4 seconds … at which point (if all the Combo Point builder attacks hit) you’ll have 3-4 Combo Points (4 if using Cheap Shot to open from Stealth) before including any Setup procs resulting in a “free +1 Combo Point” from Dodging (which also helps avoid incoming damage at the start of the engagement).
The key point here being that the beginning of an engagement is usually the most dangerous/damaging part of any fight when opening from Stealth (due to aggro adds and so on) when the Target’s attacks are all available (because cooldowns). Having the highest Dodge (and later, Parry) chances at the beginning of an engagement will tend to deflect/defer the heaviest incoming damage from the start, improving survival and longevity … particularly over multiple engagements and/or in sustained heavy combat.
One other point worth mentioning is that in previous Subtlety Rogue builds I’ve played, I’ve invested in 3/3 Initiative for a +75% chance of +1 Combo Point (for “free”) when opening from Stealth using Ambush, Garrote or Cheap Shot, which actually can make a significant difference in tempo from opening when you figure that 1 Combo Point costs a minimum of 35 Energy or the equivalent to 4 seconds of time duration. Shaving 4 seconds off the opening build up to 5 Combo Points can be a significant advantage in terms of shortening your build to finish cycle when attacking from Stealth.
However… the thing is, that’s 3 talent points for a chance of +1 Combo Point per opening attack from Stealth. 
In the context of the rest of the build, that’s not exactly a great return on investment (especially in a talent build this tight!). 
In the end, in my own estimation, those talent points were better spent “elsewhere” on talents that could yield MORE than +1 Combo Point per opening attack from Stealth during a fight (hence Ghostly Strike, Lightning Reflexes, Setup, Ruthlessness and Relentless Strikes) or would reduce demand for rapid refresh by Finisher (Improved Slice and Dice) leaving more opportunity for other Finishers to be used as dictated by circumstances.
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From a defensive standpoint, the “common knowledge” conventional wisdom is that 440 Defense is needed to push Critical Hits off the hit table, which is +140 Defense above the 300 Defense (base) skill cap at Level 60. This equates to a +5.6% Dodge and a +5.6% Parry chance for that +140 Defense above 300 at Level 60. However, this build features 5/5 Lightning Reflexes and 5/5 Deflection, which is the functional equivalent of adding +125 Defense to the build from talents (since 1 Defense = +0.04% Dodge AND +0.04% Parry, so +1% Dodge AND +1% Parry = 25 Defense at Level 60). This then leaves a “gap” of 0.6% chance to be critically hit or +15 Defense that needs to be made up for in order to push critical hits/crushing blows off the hit table when being attacked (empirically speaking, in a vacuum).
Ah, but then … this build invests in the Sleight of Hand (2/2) talent, which reduces the chance to be critically hit by melee and ranged attacks by -2%. That means that no additional Defense is “needed” at Level 60 in order to push critical hits off the hit table when attacked by Level 63 raid mobs. 
Note that Sleight of Hand is taken for this “defensive” reduction in critical hit chances (which can improve Time Till You Drop enough to be survivable), rather than reaching for the improved Threat reduction when casting Feint (that’s just a convenient bonus).
This then means that from a “defensive” standpoint, this build invests into each and every single talent that can bolster and improve dodge/parry/disarm protection from incoming attacks … Lightning Reflexes, Deflection, Riposte, Sleight of Hand and Ghostly Strike … at an investment cost of 14 talent points in total. Individually, these investments will tend to “tinker at the margins” of performance, but collectively when taken together make for a very strong supplemental buttress to protecting yourself from incoming melee (or ranged) damage, either in PvE or in PvP.
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But then on top of all of that, there’s also Ruthlessness in Assassination for a 60% chance to put +1 Combo Point onto your target after casting a Finishing Move. This is essentially the counterpart to Initiative in the Subtlety tree. However, the capstone to all of this increased Energy efficiency and Combo Point generation can then be found in Relentless Strikes (for a chance for a free Energy after using a Finisher). This talent actually generates Energy for you, depending on how many Combo Points you spend on your Finisher (it’s a 20% chance per Combo Point, so 100% chance with a 5 Combo Point Finisher). This Energy rebate after a Finisher provides you with the Energy boost needed to reduce the number of Energy recovery ticks to fuel your Combo Point building even further, which then has the effect of speeding up the Build To Finish tempo to be even faster.
And that’s a HUGE advantage … because that then lets you choose between multiple options, such that your Rogue can then use whatever Finisher is needed RIGHT NOW as the situation and circumstances change. You’re not locked into doing only ONE thing well, you can do any of a number of different things reasonably well every time your Rogue has built up a stack of Combo Points to use on your target.
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Now, one downside to getting free Combo Points out of Setup is that the talent is only doing something for you if you’ve got aggro and are being attacked in melee (which you can Dodge). Setup isn’t helping you against Ranged or Spell attacks that much. For that reason, I decided to invest in the offense/defense talents of the Combat tree … meaning Lightning Reflexes (+Dodge) and Deflection (+Parry) to help mitigate the incoming damage that necessarily results when intentionally putting yourself into melee combat and being attacked. This then enables investment into Precision (+Hit Chance) and Riposte (Disarming counter following a Parry) for even further defensive benefits. All of this combines to make my Rogue something of an Evasive Off Tank that wants a little aggro (1v1 is best), rather than all of it, in the grand and glorious tradition of Scrapperlock. This then helps take some of the pressure of adds off a Main Tank, promoting a divide and conquer posture in a group, or promoting increased survival rates when soloing.
Incidentally, because of how “defensively advantaged” (or invested, if you prefer) this build is, I would argue that the best race choice for playing it is Night Elf, because that +1% Dodge chance (and +1 Stealth Level) aids your Rogue in being a better Dodge Tank, which then increases the usefulness of Setup to the build overall (slightly…). It’s not enough of an advantage to rule all other race options out, but it is something worth considering, particularly when playing with an especially heavy investment into Agility. This really is a case of using your Defense to augment your Offense (more on this below).
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Other investments that I made were Malice (+Critical Chance) and Improved Ambush (+CRITICAL CHANCE!). This means that I’m looking at a Dagger/Ambush build, which then leads to an Ambush, Hemorrhage, Eviscerate cycle of Build To Finish for engagements that need to completed quickly.
Opportunity and Serrated Blades by contrast maximize Garrote and Rupture damaging bleed effects. Bleed attacks like Garrote and Rupture are great against high armor targets, since their damage production is not reduced by armor … but not every target will bleed. A significant number of targets are Immune to bleed effects (skeletons and many elementals, for example), so even when Garrote and Rupture can do the whole “you’re already dead, you just haven’t gotten the memo yet” Damage over Time stunt, there are going to be times when it won’t be your best course of action (and against Immune types, it’s not even an option you’ll want to use).
So here, I’ve got different options for opening depending on whether my target can bleed or not, and whether it can be Stunned or not. This allows my Rogue to adapt to a variety of different situations and circumstances with relative ease. I can either use spike damage with an Ambush, pressure damage from a Garrote, or crowd control using Cheap Shot to open from Stealth, so as to remain flexible enough to take on pretty much almost anything. 
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I include Camouflage as a Quality of (Pickpocket) Life improvement, allowing my Rogue to Pickpocket with relative impunity (thanks to heightened mobility), greatly supplementing my generation of cash flow (and eventually Ravenholdt Manor reputation), even from the earliest levels of the game. Playing on multiple vanilla servers, my Rogue had about 2.5x the gold on hand of any of my other alts, and that’s including having to bankroll other alts at times when it comes to expenses (class training, profession training, etc.) that they aren’t able to immediately afford. Being able to just stroll through and Pickpocket EVERYTHING in an area can just be a tremendous help to all kinds of funding issues … especially when you realize that the “yield” of Pickpocket attempts (in terms of cash) are dependent on YOUR Level, not the Level of your victim(s)! This means that it can be advantageous to return to lower level zones to Pickpocket swaths of mobs and wind up with GOLD when adding up all the loot (cash and vendor bait, combined). Level 1-5 mobs in starting/tutorial areas (that can be Pickpocketed) are FAIR GAME, because they tend to get killed off and respawn (with fresh loot in their pockets) thanks to new characters starting in those areas.
And last but not least, I’ve chosen Improved Slice and Dice over Improved Eviscerate. My reasoning and rationale for this choice once again comes down to the tradeoffs of efficiency versus expediency. Extending the duration(s) on Slice and Dice will reduce the tempo at which I’d need to “refresh” the Slice and Dice buff, thereby allowing me to save entire Build To Finish cycles that could have otherwise been used on other Finishers. Being able to extend a 1 Combo Point Slice and Dice from 9 seconds to 11.7 seconds has a lot of value when you can throw a 5 Combo Point Rupture/Eviscerate/Kidney Shot … get 1 free Combo Point added to your target from Ruthlessness (60% chance) and 25 Energy from Relentless Strikes … which is exactly enough to pay for 11.7 seconds of Improved Slice and Dice, during which you’re basically doing 30% more Damage Per Second (due to the weapon haste at rank 2) rather than getting only a +15% damage bonus on an Eviscerate. The main point I’m wanting to make here is that Slice and Dice is a Finisher you can get good mileage out of even when using it at 1 Combo Point (when it is arguably most efficient) as opposed to Eviscerate which is really only most efficient when used at 5 Combo Points. So Improved Slice and Dice makes for a good low-hi mix to throw in after using a big 5 Combo Point Finisher … and in PvE combat, you can arguably get more damage production out of the extra seconds of time you spend attacking relative to what you would have gotten out of an Improved Eviscerate. The difference, however, is timing (spike damage versus what amounts to DoT).
). That’s because its functionality basically boils down to 2 “free” Combo Points on 1 target every 2 (or more) minutes … which is nice … but it’s merely nice (when I remembered to use it at all). Just the sheer lack of use I was putting into (and getting out of) the talent made me start to question my desire to go all the way to the end of Subtlety for it, in terms of investment. 
