There are three factions (empires) in PlanetSide 2: Terran Republic (red and black), New Conglomerate (blue and yellow) and Vanu Sovereignty (purple and cyan).
How to choose a faction?
If you are a new player, choosing a main faction for yourself – create a character for each faction and try things out for yourself. Listen. Absorb. Try to get a feel for the faction as a whole: visuals, sound effects, general ideology and style.
“Do I like what this faction is about?” – is the question you should be asking yourself. The description of factions below should help you answer that.
Do not choose a faction based on perceived power of a certain vehicle or a weapon – things get nerfed, buffed and reworked all the time.
Weapon traits: Generally, TR weapons have high rate of fire and big magazines. Long reloads, low projectile speed and high DPS. Use conventional gun powder weapons.
Empire-specific weapons – miniguns (chainguns).
Vehicle traits: high sustainable speed, high rate of fire, big magazines (where applicable). Prowler main battle tank and MAX unit can lockdown themselves in place to further increase rate of fire and projectile speed.
Engagement style is militaristic: get there fast, dig in, and obliterate any opposition with a rain of fire.
Weapon traits: Generally, their guns have high damage per bullet, but low rate of fire. Medium projectile speed, medium reload time. Use coilgun and railgun tech.
Lowest horizontal recoil and highest vertical recoil.
Empire-specific weapons – shotguns. All factions have access to shotguns, but NC have Jackhammer – NC HA-only burst fire shotgun, and they also mount shotguns on their vehicles and MAXes.
Vehicle traits: increased armor, high damage per shot. Reaver ESF has the strongest afterburners and really hard hitting weapons, especially up close. Vanguard MBT and MAX unit can shield themselves to absorb incoming damage, and also deal damage in bursts.
Engagement style is guerrilla warfare: hit first and hit hard.
Weapon traits: Generally, their guns are easier to hit things with. Fastest reloads, medium DPS. Most of VS weapons don’t have bullet drop, which helps at long-ish distance shooting. Use plasma or energy weapons. Medium horizontal recoil, lowest vertical recoil.
Empire specific weapon mechanic – charge: hold fire to charge up a more powerful shot (three weapons currently have this mechanic, Vortex – AV MAX weapon, Lancer – VS ESRL, Phaseshift – hybrid sniper rifle, Spiker – sidearm). VS HA-only weapon: X2 Lasher – fires balls of plasma that deal splash damage.
Vehicle traits: maneuverability (don’t confuse with speed) and utility. Magrider MBT is a hover tank that can strafe to dodge rockets and cannon shells, its faction-specific ability is a dash-like turbo boost.
VS MAX ability is Zealot Overdrive Engine, which allows the MAX to move quicker and deal more damage at the cost of receiving more damage. Scythe ESF’s unique slim frontal profile make it a hard target in head-on fight. VS faction traits are hard to calculate in numbers, how exactly useful they are depends on individual player.