Daggers, Maces, Axes, Fist Weapons and Swords - Oh My!
A rogue without a weapon is a dead rogue. Rogues are not casters, rogues don't pummel, rogues don't jab with their fist. Rogues stab or cleave with two weapons coated in poisons. The only casting we do is when we need to heal ourselves, eat some food, run and vanish into the shadows.
Weapons for a rogue really depends on what you are going to be doing, and what spec you are in. Most rogues are dual spec and if you are not, you are losing out on some dps. Combat is one of the specs that you must have as a rogue in WoD. Your second spec can be either subtlety or assassination. The reason behind dual spec is you want to be able to have an arsenal of choices at your disposal. I cannot speak for the PVP side but I do believe this would apply as well for them.
Here is where the rogue becomes somewhat broken in raid settings. This took awhile for me to understand, and I am still trying to understand why our class is this way. Each spec should be able to hold their own whether on a single target or three or more bosses. Yet the logs, recount, or Skada will tell you exactly where you stand in dps.
My first rogue that I worked on leveling was a subtlety rogue. I did not dual spec her until I was around 70 and saw a combat rogue just blow the dps out of the water. Old school rogues of subtlety or assassination had to pick up combat this expansion if they wanted to have a viable place in raiding. The combat rogue is meant for cleaving multiple targets at once with blade flurry and killing spree. Those who where combat only found themselves at the bottom of the dps charts on single target bosses. So, the pain of learning a dual spec began for a lot of rogues this expansions.
As to the weapons, we can use daggers, fist weapons, maces, swords or axes; however, there are rules that apply to each spec.
* Assassination rogues need to have two daggers in hand to be able to cast certain spells like Mutilate.
* Subtlety rogues want to make sure they have a dagger in their main hand, but can have a slow cleaving in their offhand if no other dagger is available. This allows for them to cast backstab. With that said, subtlety rogues really need to have two fast daggers in hand.
* Combat rogue can have two cleaving slow weapons in both hands, or dagger in main hand and cleaving in offhand. However, depending on what you are doing. and how many targets you have will depend on what weapons you have where. This has been a huge debate over the last several years, and I imagine it will continue on until the combat rogue has more clear rules about what they should do. The best bet for combat rogue is to have a cleaving low weapon (fist weapons, maces, swords or axes) in their offhand to ensure to you maximizing your Mastery: Main Gauche and causing more physical damaging with your passive spell Ambidexterity you learn at 10, and for your attunement: Combat Potency. With that said, sometimes axes, swords, maces, and fist weapons do not drop while leveling a combat rogue and so two daggers will be used until you get a better weapon. It will be a dps lost but no weapon is a bad thing for a rogue.
Below is a chart with some of the specialty spells that each spec has. I have include the link for where you can check out more information on this chart and what makes each spec unique.
The chart above is from http://www.wowhead.com/class=4/rogue
For more great information on rogues and their spells, check out this site: http://wow.gamepedia.com/Rogue_abilities
This site has a very clean feel to it without a lot of lag to slow you down.
Finally, I did not touch on it too much but here is a short explanation of slow and fast weapon speeds.
"Weapon speed is a number that represents the relative speed of a weapon to other weapons. Like attack speed, the lower the number the greater actual speed of the attack, so the number should be interpreted more like a delay number." (http://wowwiki.wikia.com/wiki/Weapon_speed
And here is a link to a forum discussion about 4 years ago (2011) which is still pretty viable today on speeds of weapons. http://us.battle.net/wow/en/forum/topic/2353276063
If you looking at the weapon picture you see how much damage it does per second. The Voracious Souleater
does 427.23 damage per second. This is where all that math comes into play and if you hated math in school but want to know more, get your calculators out or ask a mathematician to do the figures for you.
In the end, no matter what spec you decide to play, just keep your weapons handy, know when to sneak up on your opponent and know when to vanish into the night.
I hope this has given you some insight about the different specs of rogues and their weapons.
PS - Trivia info: If you did not know it, you will now, there are 1335 daggers in the game and some of those change color depending on your faction. (As of 8/25/2015)