Not too long ago Blizzard introduced a new stat, called Expertise, to the game. Expertise, like Hit Rating, increases your chance to hit by decreasing the possibility that your attacks are dodged or parried. Parries can be removed from the attack table by hitting your opponent from behind (more on that later), but as we saw above, we must take into account the 6.5% dodge chance. Expertise Rating lowers this dodge chance, thus increasing the chance that our attacks hit. To reach the "Expertise Cap," of 6.5%, we need 103 Expertise Rating. At this time, I don't believe that can be reached, being a relatively new stat, but look for it to show up on more gear in the future. However, Combat has a talent that increases Expertise (not Expertise Rating) by 10. One point of Expertise reduces the chance our attacks are dodged or parried by 0.25%. Thus, the 10 Expertise we gain from the Weapon Expertise talent lowers our target's dodge/parry chance by 2.5%.
Let's look at the attack table from before, this time with 10 Expertise:
- 1-18: Miss (18%)
- 19-23: Dodge (4%*)
- 23-48: Glancing Blow (25%)
- 49-94: Critical Strike (45%)
- 95-100: Hit (8%)
* - lowered due to Expertise
As you can see, as we approach the Hit / Expertise caps, your DPS increases because you are hitting your target instead of missing or being dodged. Just for posterity, let's look at an ideal attack table for a Rogue with a more realistic 30% crit chance who has reached the Hit and Expertise caps:
- 0: Miss (0%)
- 0: Dodge (0%)
- 1-25: Glancing Blow (25%)
- 26-56: Critical Strike (30%)
- 57-100: Hit (55%)
In the simplest terms, this Rogue who has hit both the Hit and Expertise cap is doing far more damage than a Rogue with the same amount of crit, but no hit or expertise rating. When combined with Combat Potency for more energy, and Dual Wield spec for more off-hand damage, you can begin to see why Combat rogues are capable of such high DPS.Positioning
The place that you stand while attacking has an effect on your DPS, your health, and your tank's health. The reason for this is due to the way that a Parry works in the game: after a Parry, you attack instantly; similarly, if your attack is Parried, you can expect an instant counterattack on the mob's current target. If you are soloing, this means you. If you are in a raid, this means your tank. In a boss fight, getting parried can be devastating -- bosses hit for far more damage than other mobs, so any time they get an extra attack is that much more damage your tank has to try to live through or avoid, which in turn puts pressure on the healers.
Also, many mobs have an ability called Cleave, which hits multiple opponents in a 180 degree arc in front of them. As a Rogue, you do not want to be eating this damage. It's more work for the healers, who should be focusing on the tank.
"How can I avoid being parried?" I hear you saying. Luckily, it's pretty simple -- always attack from the back. Not the side, the back. Attacks made from the back have no chance of being parried -- this means you increase your chance to hit by decreasing your chance to be parried, and you don't give the target any extra swings to use against your tank. In boss fights, this is an important rule to follow. If you can't attack from the back, try to hit from the side, as close to the back as you can.
Again -- always attack from the back (whenever possible). After all, Rogues do it from Behind
I am of the opinion that Combat Sword is the strongest build available for a Rogue who is starting to raid -- followed by Combat Mace, Combat Fist, Combat Mutilate, Combat Hemo, and Combat Shadowstep. The extra attack given from Sword Spec is invaluable, and can be triggered by an off-hand attack (note: off-hand sword attacks with sword spec trigger a main hand sword attack). The remaining specs I have listed decrease in effectiveness for raids down to Combat Hemo (which gets a bump once you get to 25 man raids). While you can raid with other specs, this guide is written for rogues who are looking to maximize their effectiveness, and thus I will only mention the above specs. Please note I am not recommending Combat Daggers, mostly because it is difficult to do anything but raid with that spec, and many rogues just starting to raid are still spending a significant amount of time farming.Combat Sword/Mace/Fist - 19/42/0
These builds are identical except for Weapon Specialization. Simply shift the 5 points to whatever weapon spec you desire. This is currently the most powerful Rogue DPS build available.Combat Mutilate - 41/20/0
Uses daggers, but does competitive damage in smaller raids. Damage output suffers if your target isn't poisoned, but that shouldn't usually be a problem unless you come up on an immune mob. Requires you to attack from behind, but you should already be doing that in a raid anyway. This can be more fun to play, but requires a lot of concentration to stay on top of the damage meters. Should be even more competitive in 2.4 when Mutilate gains a talent to increase its crit chance by 15%.Combat Hemo - 0/38/23
There are a few possible variants of this build, but I would suggest you use this as a template and tweak it if necessary. I think that due to the lower energy cost of Hemo, you can afford to put the 2 points in Dirty Deeds rather than fill up Combat Potency. You will likely notice a drop in your DPS on longer fights due to the loss of the talents from the Assassination tree, but in larger raids the Hemo debuff should make up for it.Combat Shadowstep - 0/20/41
Those that refuse to drop Shadowstep but still want to raid should try this build. Like Combat Hemo, your personal DPS will suffer but a larger raid should just about make up for it. I can't recommend this build for serious raiding, but if you don't have the money to respec for raids the points in Combat will help you out a bit. I haven't raided with this spec, but I can't imagine the DPS is competitive on anything but trash fights.
More information on technique, gem and gear selection for these types of builds can be found on the excellent Roguecraft 101
thread over on the Elitist Jerks forums.