Specializations

"Specializations: Receive early access to six Specializations, available at launch on Xbox LIVE, and use them, one at a time, to achieve higher ranks in your Spartan career. In addition to gaining access to new ranks, Specializations unlock new customization options."

- EB Games Australia Halo 4 Limited Edition Page.

Specializations are one of the new features in Halo 4. The Specializations are a 'perk like' system for Halo 4. It was first announced along with the Halo 4 Limited Edition.

There are a total of 8 specializations, 2 of which will be available at launch (Wetwork & Operator), the rest being unlocked later. Those who purchase Halo 4 Limited Edition will have access to all 8 at launch. However, an email sent on October 15, 2012 states that Standard Edition Halo 4 owners who play the game while connected to Xbox LIVE by November 20, 2012 (two weeks after release) will receive early access as well.

The Different Specializations
Each specialization offers a unique 10 levels of unlocks, the first 9 levels unlocking different permutations including armor, weapon skins, emblems, visors, and eventually, at the 10th level, a unique game changing perk.

Wetwork
The Wetwork mod gives the Spartan IV a few stealth benefits. The Wetwork armor mod allows the Spartan to sprint more quietly and assassination animations are faster, resulting in quicker assassinations. With the Wetwork armor modification, instead of showing up as a red figure on Promethean Vision, foes will only be able to see the outline of your figure.

Pioneer
The Pioneer's Fast Track mod allows the Spartan IVs using it to gain experience points leading to the next rank at a faster rate. Keep in mind though, For Fast Track, you only get extra XP for the amount of time you were using it. Activating it at the end of a match isn't going to net you extra XP for actions earlier in the match.

Engineer
When ordinance drops are activated, the Engineer’s Drop Recon armor mod provides an advantage. A couple extra seconds before other players see the drop coming down, the Engineer gets alerted on the incoming drop. Based on the distance to the weapon, you can get an arrow pointing you to where the nearest timed ordinance drop is coming in. It extends the range of those popping up on your HUD.

Tracker
When recieving an ordinance drop, you may not always find what you desire out of the three choices given to you. With the Tracker's Drop Recon mod, you are able to get an all new selection from the ordinance drop you call in.

Rogue
When under fire the player will flinch less thus allowing a steady aim on target.

Stalker
The Stalker packs the Nemesis armor mod, a passive skill that causes an icon of the last person that killed you to appear on the HUD. It also tracks enemies who've attacked but not killed you as well, making it useful for both retaliation and revenge.

Pathfinder
Pathfinders enjoy the Gunner mod, which reduces the cool-down on vehicle weapon overheating and allows you to move faster when carrying a detached emplacement.

Operator
The Wheelman armor mod the Operator carries gives you a bit of a resistance against EMP shots against a vehicle you are driving. It won’t necessarily stop you in your tracks anymore. This also allows you to recharge the health of a vehicle slightly faster.