The story is centred around the human homeworld Ava, which, thanks to precursor artefacts, created a small (compared to other races; a mere hundred or so planets) empire in a thousand years after finding them. However, Ava's first colony Hades, aggravated by Ava's total free marketing ideas (i.e. no workers' rights), revolted and turned
communist collectivist, taking fully half of Ava's colonies with them and renaming themselves the Red Blok. This forced Ava to cancel the debts of, and grant full membership into the U.N.A., to the remaining colonies in other to stop them from joining the revolt. Civil war soon followed.
Then the precursors showed up, with giant chain-smoking apes with big guns.
Turns out the Therians, a race of Transhuman Internet junkies are the real humans having reached The Singularity over half a million years ago. One of their pet projects happens to be taking over the universe in order to stop it from dying in about 25 billion years. They do this by seeding worlds with humans, giving them databases of information to speed up their development and waiting until the planet's resources are used up, whereupon the Therians come in and blow it up so they can use what's left to make a Dyson Sphere, which the Therians then move.
However they did not foresee the U.N.A. and the Red Blok joining forces and driving them out before they could destroy Ava, but not without a heavy price: the Red Blok lost a large bulk of its forces and half of Ava's population was killed by the Therians altering the planet to be more Earth-like. This marked the first time in over one hundred thousand years anyone had defeated the Therians. This event is known as The Trauma to all parties involved.
43 years after the Trauma, the U.N.A found the Therian world that launched the invasion (for the Therians it's more like a transport ship), Damocles.
The main factions of the game currently are:
- U.N.A.: The main faction of the game. Based on the home planet of Ava, the U.N.A. is a parody of Objectivist America, where liberty, capitalism and prosperity are hailed as the best things in life. Their Elite Army is the Jacks of All Trades of the game, with units useful for anything but lacking in number and toughness.
- Red Blok: An alliance of former U.N.A. colonies who've adopt a collectivist doctrine where the individual works for the greater good. They are the main adversaries of the U.N.A. Although their troops are not as good as others, they make up for it through numbers, resilience and firepower.
- Therians: The original humans. After reaching a singularity point in their technological prowess, the Therian became immortal, now living inside a cyberspace known as the E.M.I. grid, and want to stop the universe's decay, having planted the Avans to facilitate that but then having been repelled by them. The Therians have the most powerful and numerous units and weapons, but lack any form of effective strategy.
- Karmans: A race of giant apes created by the Therians. They serve the Therians but, in contrast to their masters, their race has adopted a strictly benevolent (as well as eco-friendly) philosophy and struggle with their role as underlings to the Therian. They can be fielded only in small numbers and their vehicles are fragile, but most of their weapons have very high rate of fire and are very powerful.
- Cogs: A formerly huge empire of aliens who fought the Therians. Brought to the brink of extinction and with only four lineages remaining out of dozens more exterminated, the Cogs' ambition is to take their revenge on the Therians. They are a whole race of clones and their armies are somewhat of a Glass Cannon.
- O.N.I.: A rising Avan Megacorp that's become the greatest provider of mercenary troops in the galaxy, among other businesses. They are known for employing hordes of cheap and durable zombies as foot soldiers.
- Krygs: An upcoming race, not much is know about them other than they fought the Therians and Karmans long ago, with the Karmans believing they'd killed them all.
Rackham, the game's parent company, has been liquidated, but Cyanide Studio has recently acquired the game along with Confrontation — another game from Rackham — with the potential to make a new game from it just as they did with Confrontation.
AT-43 provides examples of:
- Action Girl: A good chunk of the named characters are women, who don't hesitate to grab a weapon and stroll the battlefield. Special mention to Natalya "Bokor", the ruthless commander of O.N.I.'s V-SWAT and Alpha Atis-Astarte who is an Action Girl from a race full of Non-Action Guy.
- Ambadassador: Muse would love to be this, but Daimyo John Priest really takes the laurel. Hes the first human to have successfully negotiated a trade deal with the Cogs, acquiring their battery and shield technology by impressing them through charm and violence.
- Chekhov's Gun: Oni, Cogs and Krygs were all mentioned in the background long before their armies are released.
- Child Prodigy: Odin 0-1 and Manon 0-2 have genius level intellect at 13, having published a philosophy essay at 7, becoming physicians at 10, and becoming accomplished engineers to pilot their own walker.
- Color-Coded Armies: The U.N.A. troops are blue, the Red Blok is red, the Therians are always black, the Karmans are light blue and green, the Cogs are orange and O.N.I. troops are yellow and brown.
- Combat Medic: Medics are a common human infantry models in the battlefield. The most famous one is Captain Pavel Vrachov.
- Crapsaccharine World: Great place to live, everyone doesn't hate each up for the most part, no one is really evil, but there's the fact that Therians outnumber and outgun everyone by a factor of a billion to one and are only delaying their victory because war is too much fun.
- Cybernetics Eat Your Soul: Averted for the most part, played a bit more straight with Cogs but only for their type 3 (who are 95% machine) but that's what brainwashing is for!
- Deflector Shield: The Cogs had an exclusivity on the technology, but John Priest has managed to negotiate a technological trade so he now sports a suit able to deflect shots.
- Designer Babies: Odin-01 and Man-02 are twins whose genes were selected from Red Bloks elite, resulting in their genius-level intelligence.
- Enemy Mine: The U.N.A and the Red Blok joined forces temporarily to fend of the Therian invasion on Ava.
- Enemy Mine: The U.N.A. and the Red Blok temporarily set aside their goals in order to repel the Therians from Ava. It is noted that the cooperation was poor because of mistrust, and their alliance boiled down to "let the Red Blok soak up damage while U.N.A. recovers from the initial assault and prepares for the counterattack, then attack at the same time".
- Flawed Prototype: From the Therians' point of view, the Karman are this since they should have created an industrial-level civilization polluting their home planet. Instead, the Karman developed eco-friendly technologies. Ava was a more successful experiment, but then the Therians forgot that Humans Are Warriors.
- Fun with Acronyms: Yes. U.N.A. for "United Nations of Ava" is very close to U.S.A.. Likewise, Okamura Non-aligned Industries ominously form up the acronym O.N.I., Onis being Japanese demons.
- Genetic Engineering is the New Nuke: A few factions have dabbled in this. The Red Blok has made the designer babies Odin and Manon, but the Cog G-nocrats are the real master of this technology as they create vast armies of clones and have super-soldiers.
- Grey-and-Gray Morality: Given their general intentions, you could make the argument that the Therians are not that evil, and it's not like the other factions are saintly either. It's stated that they even allow those species that don't actively oppose their project to live.
- Hit So Hard, the Calendar Felt It: The two main factions have changed their calendar and put the "Trauma" as an anchorpoint for counting years. AT-43 means that we are currently 43 years after the Trauma.
- Hover Tank: The Karman make ample use of these vehicles because they prefer maneuverability to armor.
- Jet Pack: The Karmans put them on their main infantry units whenever possible to enhance their armies' speed. The U.N.A. Wing Troopers also use jet packs to strike from above.
- Laughably Evil: Dear lord, Therians. Frankly, it's hard to believe that these guys are the scourge of the universe on occasion.
- Lightning Gun: Several examples of these exist, but the Karman jammers are the most impressive, as they make lightning rain from above and can fry tanks on the spot.
- Little Hero, Big War: The Ava front is in fact just a routine mission for the Therians, whose only real importance to them is that they lost their first approach.
- Our Humans Are Different: The U.N.A and the Red Blok appear to be human, but they are actually the descendants of populations artificially engineered to resemble mankind on ancient Earth. The real Earth-born humans are the Therians, immensely powerful, transcendent beings who reached The Singularity long ago and created the ancestors of the other factions in the distant past.
- Our Wormholes Are Different: The Karman use "Point Horizon", a wormhole left by the Therian as a portal for Faster-Than-Light Travel and their scientists even hope to travel in time with it.
- Planet Spaceship: Zaïus, Flux's spaceship, is a moon-shaped spaceship with a diameter of 20,000 kilometers and is said to be able to lay waste to whole star systems.
- Propaganda Machine: Both Avan factions play up the success of their respective society at all times while hiding their flaws and dirty business under the carpet.
- Punch-Clock Villain: The Karmans mainly fight to guarantee their survival. Likewise, those in MercForce mainly fight because they're paid to.
- Recycled IN SPACE!: An acute AT-43 player may have noticed that the U.N.A. and Red Blok factions are basically the Western Bloc and the USSR transformed into space empires and having their cold war.
- The Smurfette Principle: There are no models of female regular troops, and the only unit that has more than one female model is a unit of medics. However, about half the special characters are female.
- Space Whale Aesop: Don't overmine or alien robots will show up and blow up your planet! Especially if they planted their artifacts all over the place to accelerate your progress.
- That's No Moon!: It seems that in this setting, you're not "on the map" unless you have a planet-sized warship.
- The Therian factory-ship Damocles is a Dyson Sphere built around a white dwarf; it's about twice the size of the Earth and about 80% of its energy output is used to constantly alter its Therian passengers' environment to their whims. The remaining 20% is used to pump out millions of war machines in preparation of their conquest of Ava. And this is just one of billions of such stations (at the very least, the whole Milky Way was converted). The Therians consider Damocles to be a small and unimpressive ship compared to their real homes.
- The Karmans built themselves their own planet-sized ship, the Zaius.
- The Cog faction T-Regulator has begun construction of one such vessel based on the Therians' and Karmans'.
- War for Fun and Profit: Several sub-factions, like Flux for the Karman and the Warriors for the Therians, have come to simply enjoy war for its own sake and plan on not finishing their wars too rapidly because it's fun. MercForce is also for war, mainly for profit in their case.
- The War of Earthly Aggression: If you swap Earth with Ava. The conflict still boils down to the home planet of the species going at war against its disgruntled colonies.
- Well-Intentioned Extremist: Most of the factions can be seen this way. The UNA are fighting for their survival, the Cogs are fighting for their independence, and the Therians are conquering worlds to preserve the galaxy and their own existence.