There are seven races in this game. Here’s the rundown on each of them:

Space Marines: The Space Marines are some of the most powerful humans in the galaxy. They are the result of heavy genetic engineering and enhancements, to the point where they can barely be considered human anymore. The Space Marines are all about tough infantry and big guns. My favorite Space Marine unit is definitely the Dreadnought, which is basically a huge mech which can be upgraded with different weapons for different situations.

Chaos Space Marines: The Chaos Space Marines are basically the Bizzaro version of the Space Marines. They follow demonic cult beliefs, and make use of inhuman beasts to do their bidding. The Chaos Space Marines do not excel in any particular role. My favorite Chaos unit is the Bloodthirster of Khorne, which is a gigantic demon that pretty much destroys everything in its path (the only unit that can go toe to toe with it is the Eldar’s Avatar of Khaine).

Orks: The Orks live for War. They fight anything that gets in their way, which includes other Orks. Most Orks are muscle-bound creatures that could tear you in half in a second. They’re not the brightest creatures, but they make up for it with their brute strength and ruthlessness. They are especially suited to close-combat. I don’t really have a favorite Ork unit, as I don’t play them very much at all.

Eldar: The Eldar are an ancient alien race. They posses extremely advanced technology, and advanced psychic powers. Nearly every Eldar squad is unique in some way, and it suited to a different role. They have very high firepower, and employ some of the fastest vehicles in the game. My favorite Eldar unit is definitely the Wraithlord, which is the Eldar’s giant walker-unit. This is my favorite walker-unit in the whole game.

Imperial Guard: The Imperial Guard is one of the weakest races in the game, and they compensate for this with their extremely high numbers. They are very tank-oriented, but they also employ infantry squads as meat shields. They also have some genetically engineered units, but they are the minority in the army. My favorite Imperial Guard unit is the Baneblade, which is the best tank in the entire game. It can single handedly take on a large number of infantry squads without breaking a sweat. If you back it up with some Leman Russ battle-tanks, then you have a practically unstoppable force.

Necrons: The Necrons are practically immortal. They are made of malleable and flexible metal, which also has regenerative properties. When Necron units are defeated, they have a chance to reassemble themselves and return to the battle, which makes them a force to be reckoned with. The Necrons are adept at both Melee and Ranged combat. I don’t have a favorite Necron unit, as I play them the least of all the races.

Tau: The Tau are relatively young compared to the other races, but they are one of the most efficient killing forces in the whole galaxy. They have very powerful technology, very good infantry, and some very good vehicles. I hate to be biased, but the Tau are my favorite race in the game by far. My favorite Tau unit is definitely the Fire Warrior infantry unit, because they can be built very early in the game, and if you supplement them with a Tau Commander, then you’ve got a very good platform for world domination.