Jedi Knight Guardian/Sith Warrior Juggernaut
These two melee-only classes mirror each other and are your classic tanks. When rolling a Guardian or Juggernaut, remember that it is your job to keep the enemies off the squishy classes. BioWare helps by giving you abilities that generate hate in PvE and other abilities that allow you to mitigate damage for allies in PvP. For instance, the Hilt Strike ability granted to the Guardian at level 14 generates extra hate, hopefully turning the attention away from whoever is being attacked. Although this ability works in PvP, unless you smack-talk another player, there really isn't a way to generate extra hate, whereas the Guard ability transfers 50% of the target's damage at you, even if it's a player attacking.
Jedi Knight Sentinel/Sith Warrior Marauder
These mirrors are your melee DPS classes, but they also have extraordinary damage mitigation, making this class perfect for off-tanking should the need arise. The unfortunate side to playing either of these classes is that you do not earn any kind of crowd-control ability until level 16, when you receive Leg Slash (or Crippling Slash). Because you're a melee class, you'll need one of your teammates to keep your targets in your range until you reach that level. As anyone who's ever played melee knows, that is far from easy. However, once you pass level 16, it is easier to keep your enemies in check.
Jedi Consular Sage/Sith Inquisitor Sorcerer
The Sorcerer and Sage exemplify what can be done when you cross healing with crowd control. Before level 10, these classes manipulate the battlefield with abilities like Force Wave for the Sage and Force Lightning for the Sorcerer. At level 10, healing is a bit difficult because the classes are granted only one healing ability, but by level 16, this class is decked out. However, watch that Force bar; it will drain quickly.
Jedi Consular Shadow/Sith Inquisitor Assassin
Shadows and Assassins have been compared the classic rogue class. Generally speaking, I agree, but not everything these two classes does is from melee range. The Jedi's Harnessed Shadows ability is specifically designed to enhance a ranged damage ability, and Sith's Mind Control ability allows you to tank. Maybe "classic" is too strong of a word -- "hybrid rogue" is a better way to describe them.
Trooper Vanguard/Bounty Hunter Powertech
The term "ranged tank" is certainly not something SWTOR has introduced, but BioWare is probably the first to intentionally build a class to tank from a distance. Because most of the enemies you'll face are ranged, it makes sense for the tank to be ranged as well. However, until these classes reach level 16 and receive Neural Dart or Neural Jolt, they do not have any kind of taunt and must rely on pure damage output to generate hate.
Trooper Commando/Bounty Hunter Mercenary
From my experience, the Commando and Mercenary are the most well-rounded advanced classes. They are truly the jack-of-all-trades in the SWTOR universe. For instance the Commando retains Trooper abilities like Heavy Armor Proficiency and Mortar Volley, which allow for incredible defense and offense respectively. Couple that with healing abilities like Kolto Bomb and you have a class that can do pretty much anything, even at an early level.
Smuggler Scoundrel/Imperial Agent Operative
Both the Operative and Scoundrel are classes that are combo heavy. They are not easy classes to get used to. The Operative has a stacking ability called Tactical Advantage. Initially, this ability is activated by defeating someone while using Shiv or Hidden Strike. However, later it can be activated by Kolto Injection. Besides increasing damage output, Tactical Advantage activates other abilities like Kolto Infusion. Therefore, it requires a rotation of abilities to be effective. If you are new to MMO gameplay, this will most likely become a bit frustrating, but if you like challenging and rewarding gameplay, you will probably like it.
Smuggler Gunslinger/Imperial Agent Sniper
At first glance, you might think the Gunslinger and Sniper's reliance on Cover would be a disadvantage in most situations. It roots you to a single location and makes you vulnerable to attacks from behind. However, when you gain Hold Position at level 10, even crouching without physical cover makes the cover mechanic more manageable. Also, the combination of Gunslinger abilities like Aimed Shot and Incendiary Grenade make him a powerhouse of DPS.
Star Wars: The Old Republic is finally here, and the Force is with Massively! We've prepared a Hutt-sized feast of class introductions, gameplay guides, lore roundups, and hands-on previews to help you navigate the launch period and beyond. And don't forget our weekly SWTOR column, the Hyperspace Beacon!