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In Real-Time Strategy games, the various factions are usually unified, monolithic entities. But fighting the same enemies in battle after battle gets boring. So the developers will often contrive some reason for fighting against your own side in single-player scenarios. Usually this involves betrayal or misunderstanding on one or both sides.

Also, the campaign mode in an RTS game often serves as an introduction to the multiplayer game. So the game is obligated to not only force you to play each side, but also to contrive reasons to encounter each possible matchup. Which includes fighting your own side.

A storyline-motivated form of the Mirror Match. Compare Enemy Exchange Program and Enemy Civil War.

Video Game Examples:

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     First Person Shooter  

  • BattleZone II has you destroy a splinter faction of the International Space Defense Force who wants peace, should you stay loyal to General Braddock. If you join the Scions, you will fight a renegade commander who does not share Padisha Burns' vision for the future.
  • After fighting remnant Nazis in the arctic in the mission "Project Nova" in Call of Duty: Black Ops and discovering the Nazi superweapon NOVA-6, Viktor Reznov and his soldiers are betrayed by General Dragovich, only for his execution via NOVA-6 to be interrupted by British commandos. The end of the mission involves him and his allies fighting the other Russian soldiers loyal to Dragovich and the British commandos to sabotage the NOVA-6 supply and escape.
  • Quite interestingly played with in Star Wars: Battlefront II, in which one mission of the 501st's campaign involving playing as Imperial Stormtroopers fighting an army of old Republic Clonetroopers on Kamino. This immediately after a mission or two of playing as Stormtroopers and fighting an army of CIS battle droids.
  • In Titanfall, the multiplayer matches show the Frontier Militia using the same Titan chassis that the IMC uses and all of them come from Hammond Robotics (A subsidiary of the IMC).Titanfall 2 reveals that the Militia stole a lot of Titans from the IMC to maintain their Titan fleet and subverts this by creating their own Vanguard-Class Titan. Averted with the single player campaign's 7th level: Trial by Fire, where the Militia launches an all out attack on an IMC airfield using the Vanguard Titans against the variants used in the multiplayer.

     Hack And Slash  


  • The Burning Crusade had this for the Blood Elves. Their prince, Kael'thas Sunstrider, had joined the Burning Legion in desperation to cure their hunger for mana. When this is revealed, Lor'themar Theron and the player turn against him. Kael'thas ends up as a boss in the Sunwell raid.
    • The entire Mists of Pandaria expansion for World of Warcraft has been building up to this situation for the Horde. It eventually comes down to Vol'jin and the other leaders of the Horde against Garrosh and his Kor'kron. Even after Vol'jin is named the new Warchief it appears that this situation could potentially pop up again. Speaking to Sylvanas following the raid shows she has no intention of listening to a troll and has every intention to see what she can get away with. Lor'themar also expresses concern regarding Sylvanas.
    • Two expansions later, a dying Vol'jin chooses Sylvanas as Warchief much to everyone's surprise including hers. After an attack on a Night Elf city ends with the murder of thousands of innocents, Varok Saurfang turns on Sylvanas. He organizes a resistance and actually gets help from the Alliance's King Anduin.
    • In Battle For Azeroth, it seems like one of these is brewing among the Alliance. Tyrande, leader of the Night Elves, refuses to sign the peace treaty with the Horde.

     Real Time Strategy  

  • In Achron the remnants of the human fleet find themselves fighting against a section of the military that seems to have its own objectives. In the Grekim campaign one of their leaders decides he would be best to lead their race, and hunts down the others. The Vecgir end up fighting against their own when they face a group of runaways that went and joined the Grekim.
  • In Act of War: Direct Action, the last two missions have you going up against Consortium troops exclusively using US Army equipment and uniforms. It's used more often in the Expansion Pack, High Treason, with the final mission even featuring Consortium troops using Task Force Talon equipment for the first time.
  • The Age of Empires series has some of this, most memorably in the Montezuma campaign of Conquerors. In the second scenario, after you defeat the Tlaxcala, your allies declare war on you.
    • Barbarossa's campaign in Age of Empires II: Age of Kings. The second mission involved attacking Poland without a Town Hall. True to history, you end up betrayed by Henry the Lion twice and end up having to deal with him in addition to existing obligations.
    • It's actually very common in Age of Empires and its sequel, often when your civilization is fighting a rival state of the same civilization, e.g. Athens vs. Sparta in the Peloponnesian War or the Dauphinists note  vs. Burgundians (both French) in the Hundred Years' War.
    • The first Salah ad-Din scenario has the Egyptians start off as your friend, then declare war on you, then become your friend again when you convince them you really are only going through Cairo to go kick some Crusader asses.
  • Age of Mythology's campaigns is a series of this. The reason for this is that the only consistent units that you control are a band of heroes who are traveling the ancient world in order to stop the Big Bad from unleashing Kronus, and that you raise armies from the people of where you happen to be. The villains do this as well, meaning that most battles involve the same units-the only difference being the gods worshiped by either side.
    • The expansion starts off fairly normal, but then turns into this again when it turns you've been fighting for the wrong side.
    • Of course, the main game has a dream sequence where you join the legions of Hades to fight the "Evil Empire", that being Arkantos's lovely seaside kingdom of ATLANTIS!!!, packed to the gills with Olympian heroes.
  • The Command & Conquer games have this as well.
    • Command & Conquer: Tiberian Dawn had an inversion in the Nod campaign where you had to take out a GDI base with stolen GDI equipment because a traitorous commander sent your normal forces halfway across the world.
    • The Nod campaign of Command & Conquer: Tiberian Sun starts off as a civil war between a GDI plant meant to keep Nod from causing trouble and the player character, a member of Nod's elite who said mole has falsely accused of treason. Later there's a subversion where you hijack GDI equipment to fight the Forgotten, who are using a combination of Nod equipment and old equipment from the original game.
    • In Command & Conquer: Tiberium Wars, Nod missions at Sarajevo and Ayers Rock involve the player Kane-loyalist Nod army facing off against rogue Nod soldiers. Also done in the Kane's Wrath expansion, the first Act involves vanilla Nod forces fighting against the Black Hand, a subfaction.
    • Command & Conquer 4: Tiberian Twilight has you fighting your own faction no matter what side you choose. On top of that, the GDI campaign doesn't have you fighting renegade GDI soldiers, you ARE the renegade GDI soldiers.
    • The Soviet campaigns in Red Alert 2 and Red Alert 3 necessitate the elimination of another Soviet general whom the Soviet leader has declared inconvenient to keep around. Of course it's only a matter of time before they try to do the same to you.
    • The Desecration mission from the Red Alert 2 Soviet campaign has you battling against general Vladimir who defected the main force because he knew that Yuri is a traitor. In later mission dubbed Red Revolution you are going against the traitorous Yuri.
    • And in Red Alert 3, when playing as the Allies you have to attack an Allied base under the command of the Japanese android US president.
    • Red Alert 3: Uprising has former Crown Prince of Japan Tatsu, now cooperating with the victorious Allies, going against the Japanese generals. And once you've got rid of the rogue Japanese generals, he then goes and betrays you and uses all the stuff stolen from those generals to attack you!
    • In Command & Conquer: Generals, the only faction that ever outright fights their own side in the main campaign is the GLA (in skirmish games, it's easy to capture enemy buildings to get access to their tech). Technically, you DO do this, but it's handwaved: Rogue Chinese General, GLA using captured US equipment from an abandoned base, et cetera. Given that they're a massing of factions rather than an army of a particular country, this makes sense. The "Generals Campaign", however, pits a general of your choosing against each of the other available generals in sequence, including the ones that share your nationality. With there being 6-7 AI generals to choose from (in a non-modded version of the game, the Infantry and Demolition general levels are Dummied Out), in a campaign where 6 are randomly chosen to fight you, it is guaranteed that you will go up against someone who shares your nationality.
    • Red Alert avoided this through the original campaigns and the Counterstrike expansion, but Aftermath did feature two Soviet missions were you go up against the Soviet arsenal, one of which is against actual, albeit radical to the point of having gone rogue, Soviet forcesnote . It also features a mission that can become this — if you follow your orders to the letter, it sticks to fighting rebellious civilians armed with an odd assortment of heavy weaponry, but if you decide not to commit war crimes at one point in the mission, Stalin's elite guard gets sent in to put down the uprising and you (and the mission objectives accordingly change to defeating the revolutionaries or the elite guard).
  • Completely averted in Company of Heroes, where even in multiplayer you can never fight your own faction. This holds true in the expansion pack Opposing Fronts which added two new factions that still cannot fight a civil war. In fact, in Opposing Fronts multiplayer, the Americans and British factions must always fight on the same side, as must the two German factions (Wehrmacht and Panzer Lehr).
  • Speaking of which Dawn of War: Dark Crusade features two scenarios with either the Imperial Guard fighting the Blood Ravens or the Blood Ravens fighting the Imperial Guard because each has their orders concerning Kronus and neither will give ground even to their own Imperial allies.
    • And of course it happens again in Soulstorm this time between the Imperial Guard, the Blood Ravens, and the Sisters of Battle.
    • The first case also has an interesting example of Rewarded as a Traitor Deserves. When assaulting the Imperial Guard's home province as the Blood Ravens, one of the optional objectives is to kill an officer in charge of a certain regiment. The regiment will immediately switch to your side and fight against their former comrades. However, the after-battle text will indicate that those guardsmen whom you killed were buried with full honors for doing their duty, while the traitors were all executed.
    • The Space Wolves were suspected to have been created as the Emperor's secret police to keep other Astartes in line. Nowadays this role is held by the Minotaurs, a (possibly Khorne-corrupted) Chapter that serves the Inquisition.
  • In Dungeon Keeper and its imitators, you spend just as much (or even more) time fighting rival Keepers as you do fighting the heroes.
  • In Earth 2150, playing as the Lunar Corporation (who were allied with the UCS) had one mission where you were both on the same map fighting the enemy together when a virus corrupted the UCS programming, turning every UCS unit on the map against you.
  • Emperor: Battle for Dune: Halfway into House Harkonnen's campaign Copec poisons his father Baron Rakan, setting off a Succession Crisis where the player can choose to fight for him or his brother Gunseng.
  • In the Star Wars RTS Force Commander you're arrested, and you have to walk up to storm troopers who are more loyal to you than to the Empire in order to escape (it's the only level in the game in which there is a unit on the map to represent you). After that, you completely switch sides.
  • Hearts of Iron IV features a civil war mechanic, where a political ideology that is not currently in power in a country may rise up to attempt to overthrow the ruling government by force. This can happen through outside influence or be purposefully triggered by the player in their own country, along with a few scripted historical wars such as the Spanish Civil War. In any case both sides will have the exact same technologies and will split the country's armies, resources and territory between each other at the start of the war.
  • Homeworld: Cataclysm has an enemy whose main weapon is an infection beam that can instantly convert your units and send them back against you.
  • In the campaign of Homeworld: Deserts of Kharak you play as one of two carriers launched by the Northern Coalition. At one point the clan operating the other carrier splits with the Coalition and they attack you.
  • Toyed with on a tactical level in MechCommander and its sequel:
    • The first game is clearly set as a Clan vs. Inner Sphere scenario, where a unified Inner Sphere army is attempting to retake worlds previously conquered by the Clans. You'd think this would have the technologically inferior but numerically superior Inner Sphere force constantly face smaller numbers of powerful Clan units, which turns out to not be the case; several missions consist of fights against nothing but hordes of Inner Sphere Battlemechs, identical in every way to the ones you can request from your quartermaster. The game justifies this by claiming that your opponent, Clan Smoke Jaguar, puts their Bondsman corps, comprised of captured and now servile warriors, into equally captured Inner Sphere machines rather than anything that's pure Clan-tech.
    • The sequel has you controlling a mercenary unit, using the notion that you are the one changing loyalties to force you to face units you once controlled. In this case, you start out working for one House as your introductory campaign, change to another House for the second act, and change again for the third. As you have a persistent inventory of purchased units, this means that you can and eventually will end up pitting units you bought from one faction against that very same faction later on. For instance, the first campaign sees you serving House Steiner against bandits and later House Liao, purchasing Steiner-made technology to do so. You then enter the pay of House Liao and the Liao Mech units you fought on the field previously are now yours to buy and use, while now you are deprived of the opportunity to purchase Steiner equipment and must face off against Steiner units, but may choose to do so with any Steiner-built Mechs you kept from the first campaign.
  • Republic: The Revolution features this as a late-game mission arc - a trusted ally leaves with half your agents, and you have to erode their support to recruit them back.
  • Rise of Legends inverts this: most missions have you fighting an enemy using the same units as you are, or dark glass versions in the Alin campaign. Only a few missions have inter-factional warfare, and all but two amount to skirmishes.
  • StarCraft story campaigns have always wanted to have you face off against all three races at some point. Most of the Terran campaigns involve fighting a corrupt government as La Résistance, but in general, coming up with a reason as to why different human groups wouldn't get along wasn't too hard. The Protoss have had some internal religious spats, but in StarCraft II, a new faction called the Tal'darim that worship the Big Bad had to be invented to provide a steady supply of opposing Protoss to shoot. The most blatant example has to be the Zerg in the original game: a slain Cerebrate's brood has gone feral and must be destroyed. Zerg vs. Zerg conflicts in later campaigns came about as a result of the prior Hive Mind being killed or depowered, resulting in the former collective's sub-leaders forming factions.
  • Stellaris: You will suffer from civil wars and rebellions if you ignore planetary unrest warnings. It can also happen to your enemies.
  • Happens a few times in Supreme Commander, either due to corruption by Seraphim artifacts or internal politics. The expansion pack goes a step further, by having the Aeon Illuminati split completely into those who join up with the Seraphim, and those who join with the UEF and the Cybran Nation to try and save humanity.
    • Notably, it isn't until the very last mission of the expansion pack that a UEF-UEF battle takes place, though during any mission, you have the option of capturing enemy units (or better still, factories), and gaining access to that tech tree. One entertaining example is capturing a Seraphim factory in the fourth mission of the expansion and building Ahwassa experimental bombers.
    • And with proper preparations (a few Salvations, Experimentals or an ACU with a nuclear tactical missile launcher) the UEF-UEF battle will be one of the shortest in recorded history.
  • Warcraft:
    • The first Warcraft game introduced this type of mission. The Human campaign had one where you had to stop a band of mercenaries from sacking Northshire Abbey, while in the Orc campaign you had to wrest control of the Horde from Blackhand. Warcraft II: Tides of Darkness expanded on this, having a couple of Alliance vs. Alliance missions were centered around traitors who for some reason decided that siding with the evil Orcs was in their best interest. The Orc vs. Orc missions involved a power struggle between two major Orc leaders, Gul'dan and Doomhammer. Then, Beyond the Dark Portal came along, and everything got complicated.
    • Warcraft III: Reign of Chaos had a fair bit of this as well:
      • The end of the Orc campaign involved squaring off against a camp of corrupted Orcs. Though the enemy orcs were much stronger counterparts of your own, they still matched up well enough. One Night Elf mission ended with a fight against corrupted Satyrs and ancients, which were the Evil Counterpart of the Night Elves.
      • Th expansion pack The Frozen Throne has a three way war between the Forsaken (Undead) VS. Scourge (Undead) VS. Dread Lord Rebels (also Undead) missions, and one Blood Elf vs. Alliance mission, the Blood Elves being a visually different but statistically identical splinter faction of the Alliance forces.
  • World in Conflict has Soviet special units take over an US base and use an absurd number of captured US vehicles in an attempt to attack New York. However, there is no chance of fighting your own faction in multiplayer.


  • MechWarrior
    • In Mechwarrior 3, a similar setup to Mech Commander is used. Despite being an Inner Sphere military unit fighting Clan Smoke Jaguar combatants, the majority of the BattleMechs you fight will be Inner Sphere designs rather than Clan. The justification used is that CSJ are notoriously lacking in Home Guard funding and equipment, resulting in them using captured Inner Sphere equipment for their defenders, while the superior Clan equipment is shipped to the front lines. Clan mechs are generally reserved for boss fights and start appearing more often towards the end of the game.
    • In Mechwarrior Living Legends, the game is set in a Inner Sphere versus Clan conflict, though server owners are free to allow players to either buy any vehicle or only faction-specific vehicles. In the game's Tournament Play with multiple Inner Sphere and Clan factions, groups could attack groups that are nominally on the same side, such as House Kurita attacking House Liao, both using Inner Sphere equipment. This is completely in-character for the Successor States.
  • A major component of TIE Fighter, as the player faces not one but two traitorous Imperial Admirals in the course of the game. Defeating the forces under their respective commands is ultimately the focus of over half of the campaigns - two of the original seven and a whopping five of six expansion campaigns feature rogue or defecting Imperials as the primary enemy. It is entirely plausible for the player to finish the game with more kills of some Imperial starfighter types than X-Wing kills.
  • Originally War Thunder featured some occasional "alternate history" or "exercise" maps where the USA were put against the UK, or where the Western Allies fought USSR, with a loose intro before the battle just to excuse the setup, like the two forces "training" before the supposed off-screen true battle against the enemy. This granted Allied players to fight each other rather than always Axis players, while also reducing queue times if possible. After 2018, for team matchmaking balance issues, fixed historical teams were removed and every battle could see a mix of various nations, or even the same nation for both teams in certain occasions, without any supporting lore.

     Third Person Shooter  

  • In Splatoon's Splatfest events, sometimes one side will be so popular that there aren't enough people on the other side to go around, so they'll occasionally be matched up with another team from the same side.

     Turn Based Strategy  

  • Picking between the nations of Hoshido and Nohr in Fire Emblem Fates had at least one mission that involves fighting an army from the nation you sided with, all of whom are fought in every campaign. From Hoshido is the backstabbing, kidnapping, murderous ninja Kotaro, from Nohr are the Co-Dragons of the Big Bad Garon, Hans and Iago, where in Conquest Corrin is forced to fight alongside them until the very end of the campaign.
  • The design of Heroes of Might and Magic means that you almost certainly will be using captured towns to churn out troops of the associated faction, if only as home guards, so specific examples may only be worth mentioning when you start with towns of the same type on opposing sides.
    • Heroes of Might and Magic IV took this to really extreme levels when all six campaigns of the original game had the main enemy of the same faction as the player. Not so much in the expansions, though.
    • Might and Magic: Clash of Heroes does the same thing, but in this case it's justified—the demon plan is to create a civil war, and they're not the one's behind the idea in the first place. There's also the bounties, who are all criminals.
    • While IV was the crowning example, it does show up in other games in the series as well — a prominent example is the end of the Song for the Father campaign in III, where many of the necromancers of Deyja ally with the forces fighting King Gryphonheart of Deyja after realising what a terrible mistake they'd done in raising Gryphonheart from the dead — mechanically represented by the mission this happens for starting with the player's side having a Necropolis with a necromantic hero in the garrison alongside the three other towns you have, while the enemy is entirely necropoli.
    • For a game about a civil war, II is relatively frugal with it (town types are less associated with states than in III) — but frugal does not mean non-existent, several misssions pits you starting with the same type of town as an enemy. Sometimes you get to decide which enemy before you start the mission.
  • Three of the episodes so far in March of War focus on civil wars fought between the various factions: Exalted Inferno, Tropical Thunder and African Sunrise.
  • Sword of the Stars doesn't have a campaign, but the very detailed fluff makes a point of explaining how the otherwise-unified races might have multiple factions in play:
    • Far-flung human colonies attempt to declare independence, and refuse to take central command's "no" for an answer.
    • The Tarka's complex hierarchical society is highly prone to political warfare under normal circumstances, this can easily boil over into military conflict.
    • A Hiver "princess" may get too big for her boots and attempt to wrest power from the existing Queen.
    • Two Liir factions can start a conflict if each considers the other Suul'ka (roughly, "soulless")
    • Zuul are by nature territorial and aggressive, infighting of various magnitudes is common.
    • Morrigi can end up at each other's throats if two sufficiently powerful trade cartels end up vying for trade routes.
    • In the second game the six races have more or less formed unified factions, but it's still possible in game for planets or even entire provinces to rebel.
  • Wargroove has a few examples. In the campaign proper, when it's revealed that Sedge attacked the escaping Cherrystone army as they enter Floran territory, Greenfinger Zawan ends his hospitality towards Sedge and asks that he leaves. Sedge resists, resulting in a Floran vs Floran conflict. There's also the matter with the bandits, whose units are reskins of Cherrystone ones, who fight Caesar of Cherrystone. In Arcade, there are a few examples where COs from the same nation fight each other.
  • Nintendo Wars sees this happen in the first Advance Wars game. For most of the campaign, the player is with Orange Star, controlling Andy, Max, and Sami as they fight against the forces of Blue Moon, Yellow Comet, and Green Earth. Near the end, it’s revealed that there’s a fifth faction, Black Hole, who orchestrated the entire war for their own gain. The first commander to appear for Black Hole is a clone of Andy, leading to this trope. On a similar note, during the battle animations, Black Hole units look identical to Orange Star units.
  • Common in Age of Wonders: Planetfall, with most of the "factions" representing species rather than united polities. The Amazon and Assembly campaigns, in fact, have a member of the same species as the primary antagonist.
  • Battletech, as per every other video game in the setting: Not only is the story mode all about fighting in a literal civil war, but barring a few quest rewards and other story events the only reliable way to acquire new battlemechs is to haul the wrecked remains of the ones your mercs destroy back to the dropship and patch them up.

Non-Video Game Examples

  • Battletech is a Feudal Future realm full of barely coherent nation-states with a very large noble class and a lot of bad blood between them: Battles between two lances from ostensibly the same faction are perfectly justifiable, and that's not counting the constant hiring and re-hiring of mercenaries to serve as deniable proxies in conflicts both internal and external. Of course, since Battletech factions are Cosmetically Different Sides for much of the game's timeline (with the time between the Clan Invasion to the ilClan era being the exception), and the constant battlefield salvage ensuring 'Mechs change sides on a regular basis, pretty much any 'mech combination can fit into every faction anyway.
  • The Warhammer World is so discordant that it actually makes sense for almost anyone to be fighting themselves. It's easiest to justify for the forces of Chaos, the Skaven, and the Orcs/Goblins, who have disunity built into their very premises, each faction consisting of countless warbands/clans/tribes perpetually feuding with one another for dominance, only temporarily halting those feuds when a particularly powerful and charismatic leader manages to direct them outwards. The "good" races don't fight themselves anywhere near as often, but with all of them being federations rather than unitary states and the lore often referencing small-scale civil wars, there's very little justification needed for why, for example, Imperials from Reikland would fight Imperials from Wissenland.
    • They also released an expansion for Warhammer in White Dwarf focusing on civil war, detailing rules for all the possible reasons a faction would have for fighting themselves.
    • Also the Blood God Khorne is known for enjoying bloodshed regardless of whose blood is shed. Followers of Khorne rarely disappoint their Master in this, whether they slay their enemies or be slain themselves.
    • In the fantasy setting, Witch Hunters are feared by friend and foe alike for their "burn first, ask questions later" attitude.
    • In The End Times, Bretonnia gets hit by one orchestrated by King Louen Leoncoeur's bastard son Mallobaude and Arkhan, finishing only when The Green Knight handle Mallobaude and Arkhan retreats.
  • The same for the Warhammer 40,000 Galaxy.
    • One White Dwarf magazine article featured a battle which the writers wanted to be the biggest battle possible. Unfortunately, the two biggest armies the writers had lying around were Space Marines and Imperial Guard, who are nominally on the same side. They came up with the explanation that an extraordinarily powerful psychic had arisen on an Imperial planet, who could mind control the entire planet, including its Imperial Guard contingent. The Space Marines were sent in to put him down.
    • The troops of the Ecclesiarchy also seldom need a reason more specific than "might be corrupted by Chaos" to battle allied Forces. The White Dwarf Scenario mission for the Grey Knights "Wipe out the Infestation" states that a Catachan expedition force might have been exposed to Chaotic influence... and so the Grey Knights have to deal with it appropriately.
    • Tyranid hive fleets, despite being one of the few truly unified factions since they have a Hive Mind, will attack each other in order to ensure the winning fleet has the best adaptations and most biomass.
    • Orks live to fight, and don't particular care if their opponent happens to be another Ork. In fact the green tide turning on itself as soon as it gets enough momentum for its enemies to no longer be an interesting fight is the main reason they haven't conquered the galaxy yet.
    • Chaos being... well, Chaos, infighting is rampant at the best of times. Apart from the ever-present "Khorne cares not from where the blood flows" adage, adherents of one Chaos God will fight follows of others or stab their fellows in the back to get ahead at the drop of a hat.
    • The Horus Heresy tabletop game is particularly open to this. The 2022 rulebook states outright that it's such a chaotic time in history that anyone's loyalties could falter and detachments of any legion could choose either side, with traitor Ultramarines and loyalist Sons of Horus being called out as entirely plausible. Games are ostensibly always between one loyalist side and one traitor side, but the manual points out the entire Imperium of Man was such as mess at the time that misleading orders could easily lead to loyalists completing heretical objectives (and vice-versa). Even the Adeptus Custodes (who mechanically can never be Traitors, no exceptions) can fight against other Loyalist armies, with the explanation the fog of war was simply that bad.