RED MAKES IT GO FASTUH!
Orks are a race of fierce and brutal green-skinned alien warriors. They are very numerous and have spread through all parts of the Milky Way galaxy. It is believed they are the descendants of a long-extinct alien species who bred them to be the ultimate warriors. Orks are extremely aggressive and live for battle, their entire society being entirely focused on manufacturing weapons and conquest. They are physically stronger than Humans, able to endure great hardships and shrug off woulds that would incapacitate a Human soldier. Orks breed via spores and their numbers can swell very quickly if left unchecked. Furthermore, these spores are difficult to eradicate, which means a planet that manages to repel an Ork invasion will find itself plagued by bands of Orks for years or even decades.
Luckily for humanity, Orks aren't particularly intelligent and their very lust for combat drives them to constantly squabble among themselves. Occasionally, a powerful leader arises and unites the quarreling Ork tribes, who then launch a massive military campaign, known as a WAAAGH! in the Orkish language. While these campaigns are often short-lived, the sheer number of Orks throughout the galaxy means there are constantly hundreds of Imperial worlds threatened by the Green Tide.
Ork don't learn skills as Humans do, but are instead born with instinctive knowledge and skills in certain fields. Unlike Humans, they never ponder why something is so or whether it is right. For example, some Orks are physically bigger than others and thus the ruling caste in their society - smaller Orks will instinctively follow bigger ones. Ork castes include:
Boyz - the most common type of Ork, these are basic footsoldiers. Their equipment varies according to their Clan. Goffs prefer close combat, Bad Moons have a fondness for heavy weapons, while Evil Sunz are balanced.
Nobz - Ork nobles. These are the biggest and meanest Orks except of the Warboss. They are armed to the teeth and are superior to any Human soldiers both in ranged combat and in close assaults.
Warboss - the leader of an Ork Warband or Horde, the mighty Warboss towers over even the Nobz. Warbosses possess a crude grasp of strategy not present among other Orks as well as a certain form of low cunning.
Oddboyz - these are Orks born with a special talent in a certain technical field. The most common among them are Mekboyz, who build and maintain the Orks' weapons and vehicles. Mekboyz are fond of tinkering and experimentation, which makes their inventions highly unpredictable but potentially extremely effective.
Madboyz - while any Human would consider Orks mad, Madboyz are so weird even other Orks consider them mad. As a result they fight in separate units and are mostly left alone by other Orks.
Wierdboyz - a rare few Orks possess psychic powers. Their powers are amplified in the presence of other Orks. Unlike most Orks, Wierdboyz aren't too keen on combat, not least because a psychic overload can cause their head to explode. As a result, many are locked up in special Towers.
Wildboyz - these are young Orks who've grown up isolated from mainstream Ork society. They are armed only with primitive weapons.
Gretchin - much smaller than Orks, Gretchin are relegated to performing menial tasks and anything else the Orks can't be bothered with. In battle they are used as cannon fodder.
Orks gather into Clans, which are not actual communities, but cultural groupings within an Ork Tribe. Each Clan embodies a distinct Ork philosophy and represents a powerful ideological force that exists outside the ever-changing tribal structure.
Ork Warbands (equivalent to Imperial Companies) consist only of Orks from one Clan - the only exception being Warboss Skroll's own Horde. An Ork Horde (equivalent to Imperial Regiments), may consist of Warbands aligned to different Clans.
There are six Ork Clans in the Warhammer 40k universe, but only three are present in Final Liberation:
Goffs are the toughest and most brutal of all Orks. Goffs dress mostly in black, with some white or red checks for relief, as they see bright colors as being un-Orky. Horned helmets are also popular. The Clan's symbol is a horned bull's head.
In game terms, their units tend to be tough, powerful in close assaults, but rather slow.
Goff-specific units include: Goff Boyz, Goff Nobz, Lungbursta, Gutrippa, Stomper, Slasher Gargant.
Evil Sunz are Orks who love speed above all else. They believe painting their vehicles bright red makes them go faster. Their uniforms are also mostly read, with some white added to highlight the contrast. Their symbol is a grinning red sun with stylized flames.
In game terms, Evil Sunz are the most balanced Clan overall. Their vehicles are fast, but usually have a short range.
Evil Sunz-specific units include: Evil Sunz Boyz, Evil Sunz Nobz, Bonecruncha, Bowelburna, Gobsmasha, Spleenrippa and, in the un-patched version of the game, Fighta-Bommerz.
Bad Moons are the flashiest and wealthiest Clan. They use their wealth to buy flamboyant, yellow-and-purple uniforms and expensive weapons. Their symbol is a yellow crescent moon with a forked tongue against a background of black flames.
In game terms, Bad Moons are the slowest clan, but their weapons have the most punch.
Bad Moon-specific units include: Bad Moon Boyz, Bad Moon Nobz, Wierdboy Tower, Battlewagon (due to a bug, this applies only to human players), Bonebreaka, Pulsa Rokkit, Giblet Grinda.