Never Split the Party

Image by IsisMasshiro.

"Don't you know? You never split the party!
Clerics in the back to keep those fighters hale and hearty,
The wizard in the middle, where he can shed some light,
And you never let that damn thief out of sight..."

— Emerald Rose, Never Split the Party

The reverse of Let's Split Up, Gang!, this is when the whole party decides that they aren't going to split up unless forced to.

Sometimes it can be taken to indicate at least a minimal level of genre savviness, for example, in situations where splitting up means that one group will later have to go find the other group. It's also a clear win in horror films where the monster/killer will pick off each member one by one.

At other times, it's clear proof of Genre Blindness; if there's only one Big Bad, and the group is running from it, staying together means that the whole scene becomes the punchline of a joke: "I don't have to outrun the bear, I only have to outrun you." Additionally, staying in a group in that case makes it much more likely that when The Millstone trips and falls, they'll wipe out at least one other person as well. In this case, it might be deemed safer to apply Let's Split Up, Gang!.

This trope is extremely common in Tabletop Games and related media, where splitting up the party can make the game a headache to run. Almost always, a split of any length will result in some players sitting around doing nothing because their characters are not present, not to mention an overworked gamemaster trying to track and manage different locations at once. For this reason, tabletop groups often won't split up even when it would be tactically advisable to do so from an in-setting standpoint — or, indeed, when they have no logical reason to continue sticking together whatsoever.

It may involve telling Commander Contrarian or The So-Called Coward, "Fine, You Can Just Wait Here Alone." Or there can be an Involuntary Group Split.

See Split and Reunion.

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Examples

Anime & Manga

• In Bleach, the heroes infiltrate Hueco Mundo to rescue Orihime. When they come across a series of corridors and have no idea where any of them lead to, Ichigo of all people tells everybody to stick together to increase their chances of survival and success. Unfortunately, Renji and Rukia call him out on his "whining" and say "A true warrior doesn't fear death." The team splits up, and this blunder nearly gets them all killed.
• Fairy Tail: During the S-Class Trial arc, Levy suggests that she, Lisanna, Elfman, and Evergreen stick together, in light of the circumstances. Meanwhile, Natsu, Gray, and Cana have all run off by themselves.
• During the Hetalia: Axis Powers Bloodbath 2010, Iceland had a feeling that something bad was going to happen and pleaded with Turkey to stay with them as it would be the safest. Of course, in the background, the rest of the Nordics got kidnapped while Iceland was talking.
• In Yu-Gi-Oh!: Capsule Monsters, the heroes are forcibly separated by monsters in the first two episodes and recognize the danger of being alone.

Comic Books

• The Dungeons & Dragons comic published by IDW states it word-for-word at one point.
• Near the start of The Sandman (1989), Morpheus and John Constantine go into a dark house. Constantine is thinking "Movies. Old dark house. Horrible menace on the loose. "Let's split up". Muffled screams in darkness...".
  Constantine: Uh... We'll stick together, won't we?
  Morpheus: Of course.
• One of the early DC Comics for Scooby-Doo has a fictional story about aliens transforming into humans. This causes tension within the Mystery Inc. when Fred orders a split up. For once, they don't split up. As usual for Scooby-Doo and his friends, the aliens are fake.
• Discussed in Supergirl story arc Red Daughter of Krypton. Guy Gardner split his team before sending them out to find another Red Lantern. After seeing what devastation that Lantern caused, he thought that splitting up was a dumb mistake.
• One Thorgal story has him lost in an underground maze with a few other prisoners. Ar a junction, one suggests they'd cover more ground if they split up, to which Thorgal responds that it's also the best way to get lost.
• Briefly mentioned in The Transformers: Last Stand of the Wreckers. It's noted that the first rule listed the Wreckers' training manual is to never split the party. Sure enough, the Wreckers splitting into two teams for the Garrus-9 mission ends up being a big contributor to the deaths that ensue.
• In one X-Men story, Colossus and Kitty Pryde are looking after the younger mutants at the Xavier school while Cyclops takes a team into the field. Kitty tries to contact Cyclops at one point, but can't raise him on the mansion's communication system. When Colossus suggests that he should reconnoiter with Cyclops' team, Kitty answers, "You mean split up? Someday I've got to sit you down in front of some good horror movies, babe."

Comic Strips

• Knights of the Dinner Table has used this exact phrase occasionally, the most memorable being when they discussed The Lord of the Rings movies.

Fan Works

• In Bleach (S) Abridged, Chad argues for this when the group come upon the multiple hallways in Las Noches. It unfortunately fails, because Ichigo wants to give him and Uryu a chance to back out.
  Renji: Hear me out... we split the party.
  Chad: Hear me out- No!
• In Mirai SMP, Subverted and then painfully deconstructed with Techno, Cooper and Travis in the beginning of the story. Their diaries urge them to stick together, which they do try to do... Except Cooper, who insists they go down a dangerous path and runs off before Techno can stop him. Techno gets an alert that Cooper will die if he opens the door that Taylor and Jordan have set a trap up in... And he's unable to stop him due to being separated from him.
• In With This Ring, the SI actually sings the Trope Namer while using his ring to depict him and his team as DnD characters in a dungeon.

Films — Live-Action

• Abominable: CJ empathetically declares that she's not going to split up and look for Karen in the dark woods which may have a dangerous person or creature in them, an opinion which ultimately prevails.
• Subverted in The Cabin in the Woods, after things have gone to shit, Curt says they shouldn't split up under any circumstances. The puppeteers behind the situation then releases a stupidity-inducing gas into the room, causing him to turn around and say they should all split up and go into their own rooms. Marty's response to all of this is a confused "Really?"
• In Horror Express the two British scientists (Peter Cushing and Christopher Lee) on a Trans-Siberian Express train tell everyone to stay in pairs for protection against whoever the film's monster has possessed.
• The initial plan of the cast in StageFright -Aquarius- is to stick together in a locked room, for they are locked up in a theatre with a killer. But then Mark remembers that there's a skeleton key in the caretaker's room, but they are unable to go there together, as it turns out that Alicia's ankle (which had sprained earlier in the film) is acting up again. Then they split up.

Literature

• In Blood Promise, when Rose leads her own group of Strigoi hunters in Novosibirsk, this is the tactic she employs. When Denis, one of the group, protests that they usually split up, she answers: "which is why you get killed...".
• In the Cradle Series, Yerin and Lindon spend most of Ghostwater separated, as Lindon is trapped in an interdimensional treasure vault and Yerin is stuck outside surrounded by the people laying siege to the place. They worry about each other constantly, and they both privately note that this is the most time they've spent apart since they first met.
• The book How to Survive a Horror Movie gives you this very advice — never separate from the group.
  "We can cover more ground if we split up." You forgot to add "with blood" between "ground" and "if".
• In IT:
  • When Bill and Richie make their first trip to 29 Niebolt Street, Bill starts to suggest splitting up to cover more ground. Richie says "Fuck that. I'm staying with you Big Bill."
  • When the cop finds Ben, Bill, Eddie, Richie, and Stan playing in the Barrens, he says that he can understand them wanting to play there, but they should only do so if they stay together as a group the entire time and don't go off to play hide-and-seek or something in ones or twos. Reasonable Authority Figure indeed.
  • When the Losers face off against IT, both in the house on Niebolt Street and in the sewers, they have to stay together because the magic that's allowing them to fight IT only works if all seven of them are together.
• Edgar Cantero's Meddling Kids has the now grown up Scooby Gang expies decide this is a more effective strategy than splitting up, which resulted in serious trauma when they were still kids. Notably the Fred expy is absent from the investigation leaving the others free to criticize his Let's Split Up, Gang! strategies as dangerous and stupid.

Live-Action TV

• Are You Afraid of the Dark?: The kids in the horror stories always deliberately try to stick together, which is understandable since, while they might not be Genre Savvy, the Midnight Society member telling the story is. A good example is when two movie theater employees find their boss collapsed in his office (from a vampire bite, as they'll find out shortly), and the phones are, naturally, dead.
  Boy: We gotta get help.
  Girl: Well, I'll stay with him.
  Boy: No, we're staying together. Now come on.
• In Boy Meets World's Slasher Movie episode, "And Then There Was Shawn", when the gang tries to hide from the killer in the library:
  Shawn: "All right, everybody, as much as this goes against my horror movie instincts, I think we should split up, that way, the killer can't get to us all at once."
• One of Us is Lying: When Bronwyn wants to split up while they look for Maeve in "One Of Us Is Dancing" Janae asks her incredulously if she's never watched horror movies. It's subverted though as nothing happens to them.
• Person of Interest. In "If-Then-Else", Team Machine is trapped and the Machine is running thousands of simulations to find a way of them accomplishing their mission and get out alive. We're shown two scenarios in which the team is split, with one group to carry out the mission while the other secures the escape route, that result in them getting killed or captured. Only the third scenario shown, in which Team Machine stays together to give mutual aid and protection, has a chance of success.
• Lampshaded in Power Rangers Operation Overdrive, where Dax warns about how they're going to get picked off one by one, but the rest of the team ignores him and splits up anyway.
• Red Dwarf:
  Lister: Okay, look, let's split up.
  Rimmer: Why? Why should we split up?
  Lister: Well, we'll do the search quicker.
  Rimmer: What's the hurry? Have you got some major luncheon appointment you have to rush off to?

Music

• YouTube has several music videos of a song by Emerald Rose called "Never Split the Party."
  Don't you know? You never split the party!
  Clerics in the back to keep those fighters hale and hearty,
  The wizard in the middle, where he can shed some light,
  And you never let that damn thief out of sight...

Podcasts

• Dice Funk: Anne confronts the headmaster alone, much to Rinaldo's frustration.

Stand-Up Comedy

• French Humorist Jean Marie Bigard had a skit on how Slasher Movie Main Characters are Too Dumb to Live. At some point the four survivors decide to split up, prompting a rant on how stupid it is, how there are plenty of situations where splitting up is a good idea^note (such as grocery shopping, where it saved him 15 minutes a few days ago) and how being hunted by a slasher is not one of them.

Tabletop Games

• The trope appears in a joke amongst tabletop role-players:
  Q: How many Call of Cthulhu players does it take to change a light bulb?
  A: All of them. Never Split the Party!
• InAdventure!, dramatic editing rules assure that the split party will rejoin up at exactly the right moment. Chase scene? A car with the rest of the party comes flying out of a side street, sideswipes one of the pursuing cars, and open up tommy-guns on the others. Fight scene? They swing in on a chandelier with sabres! Shoot out? One of the masked gun-men is the absent member of the party, and the moment the major villain unmasks himself, so too will the "henchman".
• Dungeons & Dragons
  • Wizards of the Coast used this phrase in an advertisement for Dungeons & Dragons products.
  • The disclaimer on the D&D 5th Edition Player's Handbook, on the credits page.
  Disclaimer: Wizards of the Coast is not responsible for the consequences of splitting up the party, sticking appendages in the mouth of a leering green devil face, accepting a dinner invitation from bugbears, storming the feast hall of a hill giant steading, angering a dragon of any variety, or saying yes when the DM asks, "Are you really sure?"
  • A DnD crossover set in Wizards' other game, Magic: The Gathering, has a card named Split the Party, with this as its flavor text:
  Don't.
• Played with, together with its opposite number, in Marvel Heroic Roleplaying. Here, how well a character does alone, with a single partner, or as part of a larger group respectively is part of the game's mechanics and listed on their character sheet — which can make for interesting group dynamics between characters with a high rating in "Solo" and those with higher dice in "Buddy" and/or "Team" in particular^note So that is why Cyclops and Wolverine butt heads all the time!. And one of the canonical uses for "doom dice" (the GM's all-purpose "trouble" dice pool) is in fact to split up or rejoin the party whether they like it or not...
• Mutant City Blues, a low-powered sleuth game, presents an interesting technical reason to keep the party together. When everyone are playing uniformed detectives it's not very easy to conceive of 4+ detectives all working on the same case in the same scene. But the system says that clues on the scene are automatically (or semi-automatically) available only to those with the right skill off the long long list, which is only feasible to 100% cover with the whole party. Therefore, if 2 detectives go one way and 2 other go the other (which would, in real life, make perfect sense), the first group on their scene will automatically miss all the clues tied to the skills of 2 other detectives, and vice versa, possibly rendering even a relatively straightforward case unsolvable.
• Usually averted in Paranoia. Treating the other Troubleshooters as your teammates will get you killed six times in as many minutes. Of course, wandering off alone into the various hazards of Alpha Complex will also probably get you killed 6 times in as many minutes, making the game a complicated dance of making sure that you're just close enough to nip behind a meatshield, just far enough away to abandon your partners when they get stupid or unlucky, and making sure that you backstab them more than they backstab you. You'll probably still die repeatedly no matter what you do, but at least it'll be funny.
• Can be averted in certain settings of TORG, but usually isn't. In Orrorsh, in order to overcome the Power of Fear there is a game mechanic called Perseverance which can be obtained in a variety of ways. One of them is having someone (a party member, for example) die horribly — but only if it happens offstage. Of course, gamers being what they are, no one wants to be the one that dies horribly so they'll try to arrange that it happens to an NPC.
• Most White Wolf Story Tellers in any kind of hacky-slashy situation will cackle with glee if the party is split up simply because they know that they will be eating character sheets for dinner when the PCs split up in a combat situation.

Video Games

• Baldur's Gate has an infamous notification for "You must gather your party before venturing forth." The most common reason for this announcement, which becomes really annoying really quickly, is not a deliberate attempt to split the party, but the fact that the pathing in this game is not the world's greatest and one or more of your idiot party members decided to go the long way around an obstacle (or got stuck behind it). By the time the quickest party member reaches the edge of the screen the stragglers likely won't bequite close enough to travel to the next area yet.
• Used in Beyond Good & Evil, D.B.U.T.T insists they can't split up. The characters have to later.
• In Dead Rising, if you leave a survivor in a different area, their health will slowly sap away until they die. The sequel makes the survivors wave for attention if you get too far away when you tell them to stop following you. They can't stop waving so they won't kill nearby zombies until they're attacked.
• In Enslaved: Odyssey to the West Monkey must stay close to Trip, or the slave headband she placed on him will stop his heart.
• In the first Final Fantasy Crystal Chronicles game, no matter where the players go, the camera stays with the party's chalice, a magical device that dispels the miasma that covers the world. There's nothing preventing any of the players from wandering offscreen, but they will die within a few seconds without the chalice's protection, forcing the party to stay together. If your character dies and becomes a ghost, however, being already dead, you can wander wherever you damn well please. Not that you'll be able to see where you're going if you're not the one with the map, though.
• Subverted in Social Deduction Game Goose Goose Duck, which has a a special neutral role whose goal is to pass a disease onto every player. Clumping up can be an effective way to protect yourself from an Imposter, but it’s also a sure-fire way to lose to one of these guys.
• ICO flat out requires you to be paired with Yorda, because any length of time separate from her allows the shadows to take her away more easily if you don't fight them. If they take her completely, the game ends.
• One mini-game in the Hundred Acre Wood section of Kingdom Hearts II has you going into the depths of a spooky and potentially dangerous cave. Sora and the Winnie-the-Pooh gang insist on sticking together through the cave. You have to ensure that you and your friends stick together, or else you'll waste valuable time—and you'll have to go hunting your buddies down in order to move forward.
• Knights of the Old Republic averts this in most cases, only allowing you to have between one and three of your party members (your party can reach nine or ten characters in the first game and eleven in the second) in play at a time, but it doesn't let you transition to the next area unless your three party members are close enough to the transition point.
• League of Legends:
  • Late in the games, the key damage dealers can either insta-gib one champion or unleash massive sustained damage on the entire team if allowed to live. However, they also crumple like paper if caught alone. Being down that champion is a major blow, such that one mistake caused by splitting the party can decide the game.
  • Kha'Zix has this as a mechanic. If his target is alone, his Q ability will deal more damage to them. Splitting up when there's a 'Zix lurking about is a great way to get yourself killed.
• In Left 4 Dead, break up the team and you will die, no exceptions. So it's better to never break up. A survivor grabbed by any Special Infected^note Hunters, Smokers, Jockeys and Chargers is completely helpless and is guaranteed to die unless freed by a fellow survivor. Additionally, trying to do everything alone, such as setting off panic events to get ahead, may actually bring harm to the rest of your team, which they will gladly yell at you about if you decide to run ahead. More angry players may shoot you to death or boot you from the game. Naturally, a Griefer thrives on this kind of deviant behavior before being booted off the team. If you get people who are really spiteful, they will actually let people who run ahead to keep going and if they get pounced on, the rest of the team will just take their time as the Rambo player is being killed.
• While it doesn't enforce it, in Metal Gear Online it's a bad idea to split up from a group if you are going to enter combat. If you don't have coordination with the group, then you are a lot more likely to die because the enemy will most likely come in a group when you face them. Unless you are going for a stealth attack, you will always benefit from a team mate or a couple of team mates in combat. In certain areas it lends its self better to split up and sneak rather than stick around for an outright assault.
• PAYDAY: The Heist and the sequel heavily encourages players to never wander off alone. Cops and SWAT always attack in groups and it's very easy for a lone player to get overwhelmed by them, making it difficult for the rest of the the team to run in and save the downed player.
• Primal Carnage: Running off alone as a human is almost certain and immediate death because several small dinosaurs have attacks that can pin individual humans, similar to the Special Infected in Left 4 Dead, leaving the player totally helpless unless a teammate shoots them off, while the large dinosaurs have such large health pools and do so much damage at once (Tyrant class dinosaurs in particular have One-Hit Kill attacks) that it's difficult for a single human to kill them. The only real chance of humans winning is by staying together in a tight group.
• In Sweet Home (1989), you have five characters who can either operate independently or in groups of up to three. However, it's usually best to keep everyone in teams, as a character who is working solo can easily get caught in a trap that requires the help of an ally, or get cursed or poisoned by a monster and be left completely helpless as their health fades away (and characters who die in this game are gone for good).

Web Comics

• Darths & Droids
  • In strip #436, the players manage, somehow, to fail at this completely and get split into four groups, despite the fact that they only have three players present.
  • This becomes a Running Gag; in the commentary for strip #832, it's noted that you can always split the party further. "If this involves independently moving disembodied body parts, all the better."
  • In strip #921, when Episode V starts with the DM randomly assigning locations to the characters:
    Pete: Wait a minute. You're starting the party split up?
    Annie: He's using reverse psychology.
• The Free Spirit (2014) comic "Bedbugs and Broomsticks" has Winnie enforce this by objecting to Robb's plan for their party to split up.
• From MeatShield, Dhur might be an Idiot Hero, but if there's one adventuring lesson he knows, it's that you don't split the party.
• The perils of this are a major theme of the fourth major story arc in Rich Burlew's The Order of the Stick, to the point where Don't Split the Party is the title of the book compiling that arc.
• In Nebula, Mars and Earth agree that with Sun being Not Himself, the planets should all stick together for safety, just in case.
• Penny Arcade highlights the concept in their Conflux arc, noting that game masters will often split the players' party. Tycho notes that they can instead force the players to split their own party. (This turns out to mean make them quit playing.)

Web Original

• One of the most memorable moments in Acquisitions Incorporated occurs at the climax of season three, where Aoefel, in pursuit of his Oath of Vengeance's target (and the season's Dragon), runs out too far ahead of the rest of the party and falls into an acid pit trap. As he is way too far from them to call for help, they don't even find a corpse by the time they catch up. That was the very last occurrence of party-splitting on the show ever since.
• AFK: Whenever anyone suggests it, someone objects that this isn't a good idea.
• The Spoony Experiment
  • Referenced in Spoony's riffing of the Dungeons & Dragons-spinoff board game ''Dragon Strike'': "Seriously, if you split the party, I'll wring your stupid neck."
  • Also mentioned by him when reviewing Mazes and Monsters, when the party, surprisingly enough, decides to split, he repeatedly chants 'don't split the party.' Naturally, something bad happens to the characters shortly thereafter.
  • In the D20 Live at Con-Bravo:
    Spoony: (to Linkara, after the latter suggests going to investigate the plot hook on his own) You're splitting the party. Never do that.
    Big Mike: Well, I've only mentioned thieves about five times, what's the worst that could happen?
    Spoony: He could get shanked in the kidneys and die.
  • Counter Monkey:
    • There's a whole video dedicated to the trope, entitled Let's Split Up (We can destroy the campaign faster that way.) During said video, Spoony references his earlier Dethklok campaign and how splitting the party cost LordKat and Rollo T their original characters: when confronted with a mysterious portal, Jason and Chris jumped in while the rest of the team refused, which resulted in two PCs fighting a battle intended for all six heroes and getting slaughtered.
    • Reinforced in a later Counter Monkey video, "BABOON!!!", where the party is split twice, both ending horribly. First, the team's Technical Pacifist gnome druid Fidget went to explore a secret underground area alone, while the rest of the group was asleep, and was promptly mauled by Goretusk while too far away for the team to hear her cries. Later, the team sent their elf rogue and cat-man ranger to scout several blocks ahead, and upon the Big Bad's Dragon learning about them, he sent swarms of insects after them before himself attacking. Avery (the rogue) was nearly killed, but Spoony improvised a story arc that saved her character.
• Several stories of the Whateley Universe have this, usually in Team Tactics class. Caitlin's biggest gripe with the other teams is splitting up, it gets to the point that when Team Kimba choose names for their tactics, splitting up and tackling tasks separately is deemed 'the anti-Caitlin'.
• Dingo Doodles at one point describes how her party (of three plus one npc) split in three groups, each going their sepparate ways. This is portrayed less as a danger since they're all capable, and more as torture for the poor dm who has to run three storylines at once.

Western Animation

• In The Brothers Flub, despite Fraz being irritated by his brother, he seems to hate being apart from him, when Guapo finds a new job, Fraz tries to force him to come home with him, while Guapo himself tries to force Fraz to stay with him in the new career.
• A frequent issue in Captain Planet and the Planeteers. By now the kids should know that they'll need the Captain eventually, and all five of them must be together to summon him. Doesn't stop them from splitting up to try to save the day with their individual powers.
• Johnny Bravo of all people invokes this during a crossover with Scooby-Doo.
  Johnny: (to Freddy) There's a monster out there and you want us to split up?!
• In My Little Pony: Friendship Is Magic, when the main characters have to explore a giant scary hedge maze, they realize they need to stick together. Unfortunately, they get forcibly split up within seconds by the Big Bad.
• In Scooby-Doo, Shaggy and Scooby know they will be the first to find the monster if they do split up, and insist the gang sticks together. However this often falls on deaf ears.
• South Park: Butters, both in the "Pray the gay away" camp (with his accountabili-buddy) and the class trip to an "Old West" museum absolutely refuses to leave his trip buddy.
  Butters: (after slinging Cartman's unconscious body onto the first step of the bus) Teacher... my buddy is back on the bus.
• Teen Titans
  • Beast Boy turns into an octopus and grabs everybody before they split up. He then explains the trope to the team, adding the bit where the funny guy (and strangely not the black guy) goes first. He's right.
  Beast Boy: Split up? Split up?! Did you not SEE the movie?! When you split up, the monster hunts you down one at a time, starting with the good-looking funny relief guy— ME!
  • Not to mention that, being a kids show and trying to get kids to work together, many episodes rely mainly on the fact that, without all five members, the rest of the team can't beat the bad guy. A few of the many examples include "Final Exam" (Robin), "Divide and Conquer" (Cyborg) and "Every Dog Has His Day" (Beast Boy).
• In Yin Yang Yo!, the heroes were transported into an old horror movie. When Yo suggests splitting up, Yang points out why that's a bad idea by telling a random dude from the movie 'We have to split up!' The random dude agrees, runs off-screen, and is horribly killed, thus proving Yang's point.

Real Life

• This is what the expression "defeat in detail" was invented for. Breaking your forces up into units spread out too far to support each other lets even a numerically inferior force attack your units separately with the advantage of numbers in each encounter.
  • Custer's Last Stand is an example of the above. He split his group up at Little Big Horn and that battle did not go in his favor.
  • The Battle of Midway was a US victory because Admiral Yamamoto had carefully split his fleet in a manner that would allow each successive element to come to the aid of the one before it...assuming that the US forces were as he believed them to be. Unfortunately for him, US Naval Intelligence had cracked the Japanese codes and the Americans knew what to expect, so they sent more and stronger forces. Meanwhile, the Japanese were completely in the dark about US movements. This allowed the American task force to destroy Admiral Nagumo's flotilla well before the flotillas of Admirals Yamamoto and Kondo could come to their rescue.
  • Sun Tzu mentioned this in the sixth chapter of his book The Art of War. In the moment of ignorance, the enemy force will likely split his army into several units in hopes that they will cover more ground, but this will just bring the opportunity for the other side to use his whole army to crush these units one by one. On the other hand he recommends it in some situations; baiting a trap, for instance.
• There's the Older Than Feudalism military credo, Divide and Conquer.
• Surprisingly, this trope was totally averted during The American Civil War at the Battle of Chancellorsville, wherein Robert E. Lee split his army in two versus a Union force that outnumbered his own two-to-one and gave the Union one of the most humiliating defeats of the war. Of course, the fact that Joe Hooker (the commander of the Union troops at that time) had a catastrophic crisis of confidence and started retreating before the battle even turned against him did a lot to aid Lee's victory, too.
• It happened on J.W. Powell's exploration of the Colorado River in 1869. After passing the dangerous Lava rapids by portage, they were on their way home when O.G. Howland, his brother Seneca, and William Dunn split from the main party - and were never heard of again.
• German's first three campaigns against the USSR during WWII. The Germany Army High Command (OKH), optimistic and impatient to get the war over with, ultimately split its force of 3 million men and 3000 tanks into three Army Groups. These were to pursue three initial goals 500km away and 300km apart (Riga, Smolensk, Kiev), three primary goals 1000km away and 600km apart (Leningrad, Moscow, Rostov-on-Don), and three final goals 1500km away and 1000km apart (Archangelsk, Samara/Kuiybyshev, Baku).
  Needless to say, by the time they reached the initial goals in July the problems with this approach had become apparent: all three Army Groups were too under-supplied and weak to advance without either stopping offensive operations for at least a month or redistributing forces to concentrate on taking just one or two of the primary goals. The OKH wanted to focus on Moscow alone, for questionable reasons ^note  its commanders wanted the glory and political clout, it didn't care about the economics of Germany's war effort, and they may have genuinely thought it might win the war (for some reason) , arguing that it was possible to capture and hold it with a small force which could be reinforced later. Hitler overruled this hare-brained scheme and did something sensible instead, ordering a campaign to take raw resources necessary for the German economy at Kiev (July-September) and placating the Army with a questionable advance on Leningrad (August-September). The scheme was too hare-brained for Adolf Hilter, who was himself quite prone to ill-conceived and overly grandiose plans. Let that sink in.
  Postwar evaluations of this strategic choice show that the German Army's scheme for taking Moscow was an incredibly bad idea as it would have entailed a force of just 200,000 men and 1000 tanks attacking a well-entrenched defensive force of more than 500,000 men. Even if they had succeeded, it would have left the German forces in/around Moscow extremely vulnerable to the Winter Counter-Offensive as they would have had at most 500,000 troops to hold a salient less than 200km wide and 500km long against an attacking force of as many as 1.5 million troops attacking from the north and south. Indeed, successfully taking Moscow in the face of heavy Soviet resistance could only have weakened these forces even further than in real life. Given that Soviet forces were able to advance up to 100km in a single operation in some of the actual winter offensives, an early advance on Moscow would likely have been nothing short of disastrous. Never split the party indeed.
• Lachester's Laws, as detailed on The Other Wiki, explain this trope. In brief, imagine two sides of perfectly equal soldiers. Same training, same capacity, same equipment, same position. One force is larger than the other. Engagements by the two sides can be thought of as exchanges. Every time the smaller force loses a casualty, it also loses a proportionally greater part of its capacity to deal the other side damage. For example, suppose Force A, 100 strong, engages Force B, 1000 strong. Each unit has a 5% chance to cause another to be eliminated during each exchange. B eliminates 50 of A in the first exchange. A eliminates 5. In the next exchange, B's 995 remaining men will likely destroy A, and A can expect to only cause 2-4 more casualties. As a result, A would be eliminated at the cost of less than 10 from B. Numbers count twice, as they add firepower and dilute the ability of the enemy to negate your firepower.
  • The math has been greatly simplified, but is not too difficult for those familiar with calculus.
  • Because of real-world concerns discussed on The Other Wiki, the usual formulation is that greater numbers of absolutely equal troops apply an exponent of 1.5 to the superior numbered side's capability, but before the law can be applied, you have to know all the Force Multipliers. These are any and all advantages that make a unit more effective, such as superior equipment, terrain, leadership, training, and so on. For an abstract combat game like many role playing games and wargames, the original exponent of 2 may make more sense.
  • Back to Never Splitting the Party, the absence of one character of a four-strong group not only means 1/4 of the group's power is unavailable, but the enemies that would have attacked the missing member now attack the remaining three. Using an exponent of 1.5 in Lanchester's law, the party is at about 65% effectiveness instead of the 75% you might think. Using an exponent of two, missing one member of a four person group leaves the group 56% as effective.

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