The War Sequence

And you get to fight each and every last dang one of them. ""Hear me my hordes! The spell is nearly complete! Until then, you WILL keep that whelp from interfering with my ritual. I don't care if the whole lot of you get lodged on the end of his blade. You will buy me the time I need!""

- Lord Ghirahim, The Legend of Zelda Skyward Sword

Stage of a game where the enemies begin to come out in huge droves, typically near the climax. May be part of a Zerg Rush. Increasingly common as systems have become more powerful, as it requires large amounts of sprites or polygons on screen at once. The War Sequence can cause a kind of Fake Difficulty, but looks impressive and is so fun to beat (even if it's not required you beat everyone) it's overlooked.

If you're lucky, there may be a near-equal force on your side as well, making it more of a true battle and averting One-Man Army at the same time. You'll probably be expected to carry the weight of the battle on your own, though... However, a character who beats a War Sequence without backup usually qualifies as a One-Man Army.

These are likely to be the best levels ever.

This trope is named for the informally titled "Battle of 1000 Heartless" in Kingdom Hearts II where the player must single-handedly mow down a crowd of 1000 enemies. (Which is both easier and a lot more fun than it sounds.)

Action Games

 * Rune had a scene in which you're trapped in a room, forced to fend off hundreds of zombies while waiting for an enormous door to open.

Action Adventure

 * Although in Bully, 'Complete Mayhem' only requires you to take down the four clique leaders (and their bodyguards), the rest of the school's students spend the mission fighting amongst themselves, and as a timeless mission Jimmy is free to get involved in any of these skirmishes. He also has Russell on his side to even the score a little.
 * In The Legend of Zelda the Wind Waker, you run through the entrance hall of a large castle, where many armored guards are frozen in time, like statues. When you leave, however, they all have come back to life and you have to kill them all before you can proceed. There were only about twenty of them, but they were the strongest enemy in the game.
 * Part of this is probably because you have to sneak by these enemies when you first encounter them in the game, hours earlier, since they can knock you out in one hit. But now you have the Master Sword, which can quite literally cut them down to size. It seems a sense of empowerment is vital to The War Sequence in order to be done successfully in any video game it appears in.
 * Also in The Wind Waker, the lower levels of the Savage Labyrinth contains large groups of generic enemies.
 * Again, also in The Wind Waker, the secret grotto on Shark Island has a particularly long battle sequence against a horde of various enemies.
 * In Twilight Princess the prelude to the Arbiter's Grounds dungeon is a one-man assault against an army occupying fortified positions. There's also a horseback fight against an infinite number of boar-riding moblins and finally you go sniper-style to take out the moblin home base.
 * Another time, you had to kill all the mooks in the hidden village before you could advance. Probably the best use of the bow and arrow in the entire series.
 * Skyward Sword has this as part of . It's also a direct nod to the the above two games.
 * Lego Star Wars II has one part where you must fend off a legion of stormtroopers on the Death Star. The first game has the Geonosis Arena battle.
 * Not to mention "Defense Of Kashyyyk," where you have to fight your way across a beach where a buttload of clone troopers and battle droids are doing their best impression of D-Day.
 * Ninja Gaiden II (360 version) features a long stairway corridor near the end, where the ninja mooks you haven't fought since the first couple of areas will swarm at you; IIRC, around 3-400 of them. This is no doubt done solely so you can revel is slaughtering them with all the powerful weapons you've acquired since you last fought them. It works. Well, except for the massive slowdown...
 * Once you pass the hour mark in Prototype, the whole game basically becomes this.
 * The War events are straight-out examples of this: Alex temporarily teams up with either the soldiers or the Infected. Both sides get a limited number of combatants and you have to wipe out the other side before they wipe out yours. And yes, unintentional friendly fire is a VERY real possibility and DOES count against your side (I'm looking at you, notorious Whipfist-users). And to make it even crazier, it doesn't matter how much of your side remains at the end, only how fast you did it.

Beat 'Em Ups

 * The Matrix: Path of Neo recreates the Burly Brawl sequence from the second film, though (a) there were only up to eight "real" Smiths at a time (the rest were lower-resolution and skidded away if you got too close to them), and (b) there was a mandatory trick to beating them all.

First-Person Shooters

 * The ferris wheel showdown in the escape from Pripyat and the escape from the village in Call of Duty 4. In both cases, you need to get on a helicopter before you're overrun.
 * The final sequence of the American campaign in Call of Duty: World at War is essentially one of these. If you don't call in air strikes, you can just keep fighting as long as you want.
 * After 15 years of gaming, many a Doom mod has either this or really scarce ammo; some more extreme cases have the player(s) fighting multiple boss monsters at once.
 * Hell Revealed is the definitive example; its mass-monster battles were so iconic that for years this style of gameplay was called "Hell Revealed-style gameplay", but nowadays such maps are usually just called "slaughter maps". Other important mods revolving around slaughter maps are Alien Vendetta (notable for having one of the first maps to break the 1000-monster barrier), Deus Vult and its sequel (which have maps with over three thousand monsters, sometimes attacking hundreds at a time), and Scythe 2.
 * Miniature war sequences at the finale of Fallout 3 and the Broken Steel DLC while generally the whole Operation Anchorage DLC is a giant war sequence. In the first instance, the Lyons' Pride attacks the Jefferson Memorial with Liberty Prime as support, who mows down dozens of Enclave soldiers who in turn demonstrate liberal use of air and artillery support. In the second, the Brotherhood attacks Adams AFB as a diversion to let the player infiltrate the Mobile Base Crawler sitting next to the runway. Finally the OA has the Lone Wanderer doing trench warfare against hordes of Chinese while everything around him/her is being shot to hell by artillery and bombers flying overhead.
 * Fallout New Vegas has the Second Battle of Hoover Dam, where you'll either be fighting for NCR, Caesar's Legion or alongside the former for an Independent Vegas. Depending on how you've dealt with other factions, you'll be supported by either the Boomers providing air support from their bombers, the Great Khans or even.
 * The final mission of Far Cry has the player entering a volcanic caldera with at least a dozen of the toughest 'normal' creatures in the game (the giant, rocket launcher-armed grunts) and 1-2 dozen lesser enemies (although some of them were invisible).
 * Several of the late-game areas with the Flood in the original Halo had them coming in infinite waves, as well as the final run to escape. The Library somewhat approached this but did not fully qualify. Likewise, there are also a couple areas in Halo 2 which provide an effectively unlimited amount of enemies to shoot down. Brought to full in Halo ODST there is match option called fire fight which is this. waves upon waves of enemies to shoot down. no goal, just survive as long as possible. Halo Reach continues firefight mode, and in fact overlaps it a lot with campaign (all the original FF maps were places where massive battles occurred in campaign), and in one cutscene there's a big advance of UNSC forces that the covenant meet head-on.
 * Left 4 Dead has triggers in the game that need to be tripped to advance, which do things like open gates or topple bridges to create ramps. These (extremely noisy) events summon hordes of fast, angry zombies to attack the group in a miniature war sequence (miniature because only 30 zombies appear at any one time, though it certainly feels like more and there may be multiple waves). The in-game AI Director can will also throw these hordes at you after a Boomer (a special zombie) attack, when the group loiters too long in one place, or whenever it damn well pleases.
 * Inverted in Medal of Honor with the D-day level. Here, YOU'RE the mook, along with several thousand others, being wiped out in countless numbers by an unreachable enemy. Only after about 20 minutes of dodging machine gun and rifle bullets, mortars, artillery, mines and the sea itself (and watching hundreds of hapless mooks fail to do the same) do you actually get to strike back at the enemy.
 * Hell in the final level of Painkiller is this taken it's logical conclusion. You start out at a medieval siege, go through the broken wall and find yourself in the trenches of World War One. You then move into the final zone, which is an urban wasteland presided over by a giant mushroom cloud.
 * Serious Sam has lots of WAAAAAAAARRRR!!! Sequences in store. The player will often always find himself trapped in a wide open space with dozens of enemies spawning around him at a constant rate. This often includes Beheaded Kamikazes and Sirian Werebulls coming from all directions, making you really glad that you at least have an open space to work with.
 * One such sequence - precisely, the last one before the Final Boss of The Second Encounter - even had the sky darken and then rain fire and brimstone for the entire sequence.
 * "The Last Guardian" from BFE. Over seventeen hundred enemies. Followed by a final boss fight.

Hack and Slashers

 * The PC port of Devil May Cry 4 introduces the "Legendary Dark Knight" difficulty, which basically turns (almost) every non-boss enemy encounter into one of these.
 * Chapter 1 and Chapter 5 in Drakengard.
 * It's really actually all of Drakengard.
 * Same for Drakengard 2, of course. Also, it should be noted that unlike most, it doesn't look at all impressive; the Drakengard games sadly have a terrible draw distance, so you have to be very close to the enemy to see them at all.
 * In the Dynasty Warriors series, practically every stage matches the trope.
 * It must be noted that at lower difficulty levels, the computer-controlled allied generals will be quite capable of eliminating any opposing generals you don't get to first, however, at higher difficulty levels, they Can't Catch Up. At the highest difficulty levels, this can even lead to being a rather LITERAL One-Man Army, especially in the earlier games, if you played as your side's commanding officer, and there was no way to lose besides your character or the CO's death. If you could not achieve immediate and signficant momentum for your side by killing generals and cutting off reinforcements, your side would be reduced to you alone in mere minutes, no matter how well you held off the thousands of opposing soldiers.
 * The introductory and end sequences of Heavenly Sword, where you take on Bohan's entire army. The first part of the final chapter, "The Goddess," is especially awesome, as you get to rock out using the full power of the titular sword, killing up to a thousand or more of Bohan's men before the final battle with Bohan proper begins.
 * One of the Lord of the Rings games, appropriately enough, does this with an orc battle.
 * This was the pride and glory of Ninety-Nine Nights, which boasted the ability to have over 1000 enemies on screen at any one time.
 * Onimusha 3 has a similar sequence against demons.
 * In Ninja Gaiden II, chapter 10 features a loooooong stairway. Once you step on it, the door closes behind you and you are welcome by a dozen of mooks running at you. By the end of the fight, you will have dismembered and crushed your way through not far from 200 enemies. Ironically, some fan consider the massive framerate drop that occurs during this sequence makes it even more epic due to the slow motion…
 * In Master Ninja Mode, the entire freaking game is this.
 * Japanese game Ikusagami (Demon Chaos) fits an insane 65,535 enemies onscreen at once. Don't believe us? See for yourself.

Miscellaneous Games

 * Gauntlet. Since basically every enemy is produced by Mook Makers, you'll butcher thousands of enemies in each level.
 * Iron Grip is a shooter in one mode and an RTS in the other, and in co-op the shooter players face off against the many, but expendable, troops of the RTS players. In other words, if you're playing the shooter mode the entire game is this.
 * We Love Katamari has a level which requires rolling up one million roses. Doing so in one session takes long enough that many guides recommend using rubber bands on the controller and leaving for a while. Fortunately, you can save and resume later.
 * There are two different "bosses" in Sonic Heroes, Robot Carnival and Robot Storm, which are really War Sequences.

MMORP Gs

 * In City of Heroes the developers have added zombie invasions as well as alien invasions that spawn in the open. Numbers of enemies, as well as their power level (minion, lieutenant, boss, elite boss) that spawn is based on how many heroes/villians are in the vicinity to fight them, so if you have a few dozen players you can expect to see hundreds of zombie and/or alien mooks show up for a good old fashioned curb stomping.
 * Related to the alien invasion sequence, a Rikti Mothership Raid involves heroes and villains cooperating together to do battle with an endless army of Rikti soldiers, all lieutenant rank or higher, with some among them very powerful spellcasters specializing in AoE attacks to keep teams on their toes. The battle only ends when a timer (invisible to the raiding teams) finally runs out, but players can add time by setting explosives in the mother ship's exhaust grates.
 * During the 2009 anniversary, on at least one server, a zombie invasion coincidentally occurred at the same time as the Freedom Phalanx was triggered (by a GM) to attack the City of Villains. Eight very powerful hero NPCs, a hundred villain players, and easily three times as many zombies suddenly in the same zone at the same time in a three-way battle across the zone.
 * Not to escape mention, older issues of City of Heroes behaved similarly to the World of Warcraft examples above; back before there was a limit on how many enemies a player could have aggroed, it was possible for a sufficiently tough tank to aggro an entire map (or in some cases, an entire zone!) massing a hundred enemies or more in a single location.
 * A few specific tasks act like this, as well. The infamous Lazarus Task Force has a final encounter with three of the neo-Nazi 5th Column's top brass, supported by many troops, with MANY reinforcements joining in as the fight progresses. As one player put it: "... and then the entire 5th Column ambushes you!
 * Champions Online has a Nemesis mission ("Deathray Demolition") which culminates in your character's (player-created) Nemesis trying to escape after you destroy his death ray. As a last ditch effort, he snaps his fingers, and a crap ton of his minions start pouring out of every conceivable doorway or portal and try to swarm you.
 * Kingdom of Loathing has you start and finish a war between Orcish Frat Boys and Hippies. You get a special reward if you manage to wipe out both sides of the conflict.
 * Lunia, an MMORPG, does this often. The first one happens in History Stage 1-2, where you were forced to defend a village from an oncoming orc siege. Since the game's management changed to Ijji, they changed the stage to make it much easier (as in, removing about a hundred orcs or so), and removing the whole "Defend-This-Spot-For-3-Minutes" objective, but the hard-mode version of this stage, Legend 1-2, is similar to the old version.
 * In World of Warcraft, many dungeons have AoE pulls with tons of throwaway, easy to kill mobs. One of the more exciting versions occurs in Zul'Farrak, when the players (and their temporary NPC allies) get Zerg Rushed by at least 100 trolls. The Battle for Mt. Hyjal takes this trope to the logical extreme, with waves of 8 to 20 or so enemies coming at once. There's also a set-piece vehicle battle in the Ulduar raid dungeon which is intended to evoke the feel of an epic war sequence.
 * Special mention goes to one quest in the recent Death Knight chain, in which you join an army of thousands against another army of hundreds. Somewhat subverted in that the player has no impact on the ending of the sequence, nor can you die during the battle, but it's still the biggest war sequence in the game.
 * If you're around at the beginning of the event, you can see that the enemy army consists of exactly ~300~ men. This may or may not be a deliberate Shout Out, but knowing Blizzard, it probably is, considering any other number would have worked just as well, given its resolution. (Though by no means is it anticlimactic.)
 * Deliberately recreating this scenario is a favorite technique of high level players who wish to clear a low level dungeon--rather than fighting the encounters in their designed sequence, you just rush through the zone, attracting every enemy in your path, and then fight them all at once.
 * A personal favorite comes in the Cathedral area of Scarlet Monastery. Specifically, one simply runs into the dead center of the Monastery, and punches their leader in the face - aggroing the entire monastery at once. Waves of enemies will descend upon you like a locust swarm. And if you're bad enough? You will SLAUGHTER THEM ALL.
 * A special mention goes to the final shutdown event of Tabula Rasa, in which hundreds of players gathered to defend the AFS Headquarters against a truly massive Bane invasion. Unwinnable By Design, as the G Ms simply ramped the enemies up until the defenders were overwhelmed.

Platformers

 * One of the bonus stages in Super Robot Wars spinoff ~Another Century's Episode~ 2 loosely recreates the climactic battle of Endless Waltz, with the player having to take down 1,000 Serpent mobile suits. It's a survival stage, though, and technically you only need 100 kills to succeed.
 * Following on the ending of the previous game, Mega Man Zero 2 begins with Zero being found by an army of Pantheons (basic robot grunts). When you get control, the Pantheons are coming towards you from the left, and they'll keep coming as long as you keep killing them. If you do it for too long, Zero interrupts to say "This isn't fun anymore" -- but what does he know?
 * Also in Zero 1 he has to fend off an attack on the base by marching through the desert and slashing his way through an infinite spawn of Pantheons until he reaches the boss, Fighting Fefnir of the Four Guardians.
 * Ty the Tasmanian Tiger 2 actually starts off this way. Pity no one else seems intent on helping you afterwards...
 * Terraria has the Goblin Army, a hundred-strong army of goblins with varying professions. The number increases for every person playing when one strikes. To solidify the point that this is going to take a while, they drop weapons that actually help you in taking them down easily.
 * The Ratchet and Clank series has featured them starting with the third game. They were mostly optional in that one, but Tools of Destruction featured several plot-relevant examples. (Where you had the support of two crotchety old war bots, who provided entertaining commentary.) One towards the end of A Crack In Time really stands out though:

RP Gs

 * The Granfalloon boss in Castlevania Symphony of the Night had a seemingly infinite number of animated corpses attack you (they do eventually run out) while a horrific monster, composed of said corpses, shoots beams at you. The monster returns as a boss (under its proper name, Legion) in later games, strategy intact. It's particularly horrible in Curse of Darkness, where the corpses now act as suicide bombers (and deal tremendous damage if you get caught in the explosion).
 * Crisis Core includes a series of optional missions where the player can mow down, successively, 50, 100, 200 or 1000 enemy soldiers at a time. Disappointingly, and thanks to the PSP's limited hardware, the soldiers only appear in groups of approximately fifteen at a time, with a one-on-one fight against their squad leader in between groups, which makes these battles extremely long and tedious (Having maxed out his HP and pimped out his thunder spells with fused materia from other side missions, this editor began to wonder if he had died and gone to Valhalla).
 * The final battle, considerably upscaled from the original ending. Rather than Zack a trio of grunts, he takes out practically the entire Shinra army... and then  a trio of grunts
 * Dragon Age: Origins had two smaller sequences, before the finale:
 * First, in the Dead Trenches, you team up with the Legion of the Dead at a bridge, to fight several waves of darkspawn, eventually pushing to the other site and confronting an Ogre and a Rain of Arrows.
 * Second, you defend Redcliff Castle alongside it's guards in what you've been told is the Final Battle, before finding out that The Horde is going to assault a different target, before you can get there.
 * The Big Badass Battle Sequence at the end of the game consists of fighting on four battlefields, alongside Ferelden's army, while being able to call in troops from the allies you have chosen (via horn signal), taking a break to command the rest of your companions, who are holding the line to prevent enemy reinforcements from flanking you. After assaulting your way into, then fighting through The Very Definitely Final Dungeon, Fort Drakon, you fight the Final Boss, with many of the Non-Player-Characters you've met helping you in a display of Authority Equals Asskicking,
 * The Elder Scrolls Four: Oblivion has the "Breaking the Siege of Kvatch" and "The Defense of Bruma" quests. Thankfully, you have assistance from the local soldiers in both.
 * If you've levelled up significantly before doing these quests, though, you're forced to effectively be a One-Man Army, since the enemies scale with you but your allies stay the same level throughout.
 * The final mission in the original (and about 2/3 through the expansion) of Fable has you chasing Jack of Blades; you don't have to but if you so choose you can just sit there for hours hammering his infinite supply of minions. Not only is this the greatest place in the whole game to gain XP, but if you have a large enough weapon it is really really fun.
 * The final stretch to the titular Hellgate London is filled with the usual swarms of demons fighting slightly-tougher-than-typical Templars. But inside the cathedral where demons pour through endlessly, it's up to you alone to fight to and through the gate into Hell's own battlefield.
 * The Trope Namer is the pictured segment from Kingdom Hearts II. The whole scene plays something like this: Sora is left to face literally a thousand Heartless while Donald and Goofy are busy killing the rest. Thankfully, there's action commands, which lets you kill every single one in five minutes while looking absolutely Badass.
 * Specifically, you fight two types of enemies, each with different action commands. First are the Armored Knights, who let you use "Rising Sun", which lets you fly around and wreck anything you crash into. Second are Surveillance Robots, which you seize with "Snag" then use "Sparkle Ray", a powerful laser you can aim to take out multiple enemies in one hit. This means you can win the battle easily by repeatedly hitting the triangle button, then using normal attacks on the last few mooks.
 * To clarify, there is actually a counter that starts at 1000, and lets you keep track of every single heartless you have killed.
 * Averted in Jade Empire: the Xbox wasn't powerful enough to process enough enemy AI (Jade Empire has a real-time fighting system) so they just had the 'huge army' come in waves.
 * Still, the fight with
 * One of the main features of RPG The Last Remnant are the War Sequences. The player controls up to 18 units arranged in up to 5 unions; larger battles have them facing waves upon waves of enemy unions over a huge flat plain. The most notable War Sequences are the battles at the Nest of Eagles, The Six Bases, Koenigsdorf and The Holy Plain. With some awesome Clash of Opposites music track reserved solely for these battles, they are one of the game's most enjoyable features.
 * Shenmue Chapter 1: Yokosuka was an early pioneer of The War Sequence, boasting a 70-man battle at the climax. Hey, it was a big deal back in 2000.
 * As old as Tales of Phantasia. You had to rush through a maze-like plains, defeating enemies in your path (and there were a lot), and take out the boss at the end. (See: Foe-Tossing Charge)
 * The final area of Too Human could be considered an example of this trope... if it weren't for the fact that you're slaughtering dozens of enemies in a single battle is pretty much the norm from the beginning and not just for this final level. The final level is quite explicitly a war however and in most of the game you have a group of poor bastard allied mooks following you, so it probably qualifies.
 * Of course, the mooks are with you in the final battle as well. Unfortunately, there are enemies who will kill your mooks, and resurrect them to fight against you. You don't realize how powerful the Wolfs actually are until you're on the wrong end of their rifles.
 * The first Knights of the Old Republic games feature endless waves of Sith attacking you as you make your way to the final boss. The second game's last level Sith flood is limited, but there are still a crap-ton of them.
 * In the room before Malak he locks you in a room with a bunch of droid-creating machines that swarm you and don't stop coming until you destroy all of the makers. If you have enough computer spikes, you'll succeed, but it's more fun to hold them off for as long as you can before just turning around and opening the door (he doesn't lock it).
 * By this point, you're usually an unstoppable monster, so enjoy.

Run And Gun

 * Gunstar Heroes pulls this one off as well in the form of Stage 5, the first stage you don't choose to go to. It's basically a ten to fifteen minute charge, involving you ripping through everything in sight and sound, turning the streets red with blood and explosions, and at times forcing you to drag on at virtually no health. It is hard. But it is awesome.

Shoot 'Em Ups

 * Smash TV really goes to town with this. May be considered an inspiration for Serious Sam and Painkiller.

Simulation Games

 * Various missions in the Ace Combat series really drive home the point that you are fighting a war. 6 explicates it, with the cutscene for the first mission showing that Talisman/Garuda One is (initially) just one amongst many pilots defending Emmeria, as well as the ally assistance system where helping allies to accomplish secondary objectives would lead to being able to get their help back later.
 * One of the missions of Freelancer involves taking out an alien battleship... while shaking down 6 gunboats, 3 battleships, 4 cruisers, and roughly 20 fighters.
 * In fact, the second half of the storyline is pretty much one great big War Sequence.
 * In the Free Space community, this sort of mission type is called "Battle of Endor" and many people discourage it due to the complexity, system requirements, and difficulty of making it balanced and fun, but some custom campaigns have produced very respected Battle of Endor missions, such as "Nemesis" from Inferno Release 1 and "Universal Truth" from Blue Planet.
 * Area 6 and Easy Venom in Star Fox 64 have a much higher enemy density than any other levels (both being the last rail-guided level in their respective paths).
 * In Tom Clancy's HAWX, the PC and his squadron mates are called upon to go to Rio de Janiero to protect it from an alliance of hostile nations. Cue a huge battle with dozens of planes, landing craft, and tanks, ending in a dogfight against four aces flying Su-47s.
 * In X-Wing Alliance the player's Y-Wing is inadvertently dumped out of hyperspace in an Imperial exercise area, where no less than four Imperial II-class Star Destroyers are conducting exercises. It is possible for a decent, patient player to wipe out their TIE Fighter squadrons and destroy all four Star Destroyers (by blowing off their shield generators, ion cannoning them into dormancy and lasering them at leisure).
 * As befits a Star Wars flight simulator, the last four levels consist of the Battle of Endor itself.

Stealth-Based Game

 * Metal Gear:
 * The final part of Metal Gear Solid 2 Sons of Liberty begins with Snake and Raiden cutting through dozens of Mooks (which doesn't seem like many until you remember this is a Stealth Based Game) as they fight through Arsenal Gear. Then the game unloads multiple simultaneous Metal Gears for the player to dispatch.
 * Near the end of Metal Gear Solid 3 Snake Eater an Unexpected Gameplay Change happens. The game changes to a fast-paced rail shooter with unlimited ammo and a swarm of Mooks upon which to unload it.

Strategy Games
"ADA: "Warning: Large enemy wave approaching.""
 * The final battle in the C route of Blaze Union is like this, with enemy soldiers taking up around 80% of the available squares. This is a strategy game that only lets you attack five enemies at once. It's That One Level.
 * In the Sega Saturn game Dragon Force, an entire game spent gradually taking over a seven-kingdom continent using limited engagement and careful management of generals goes down the drain when hordes of dragons--by far the most dangerous enemies in the game--appear in every corner of the map. Instead of fighting the dragons, which massacre most types of troops and just regenerate anyway, the goal is to get the seven main characters to a specific area where they can fight the Big Bad as quickly as possible. Instead of the usual all-out combat, the winning strategy is to deliberately abandon those hard-won castles and fortresses in their path, so the AI will take extra time occupying the buildings instead of waiting on the roadway to engage your heroes.
 * That was a textbook example of The Computer Is a Cheating Bastard. With a little care, insignificant ninja generals who were practically worthless normally could take out seventy or eight dragons at a time with only twenty or even ten samurai units, and deal major damage to the enemy general - then you finish them off with your next general in the second round of combat. Oh, except they were immortal and would respawn a moment later. God damn it!
 * Fire Emblem: Radiant Dawn. While the most of the FE series and indeed most tactical RPGs are nothing but war sequences, things truly get out of hand at the end of part 3 of this game, when almost every important character in the game (including a good number of peace lovers) clash with each other.
 * In an early mission of Starcraft you are supposed to hold off apparently endless numbers of Zerg long enough for the Sons of Korhal to rescue the colonists. However, as it is an early mission the Zerg numbers are not actually that overwhelming, and it is easy to actually destroy the attacking forces by just having 7-8 bunkers at each of the two entrances to the city. In the later mission where Kerrigan is captured it is also possible for the player to hold off the supposedly overwhelming Zerg attack by filling the area to the max with siege tanks and bunkers with Battlecruiser air support, although in this case the Zerg horde keeps replenishing until the mission ends regardless of what you do.
 * For a good time, use the Fast Build cheat in the former mission.
 * The Total War series completely revolves around thousand-men armies duking it out on the battlefield. The game engine was so efficient while rendering these battles, it was even used to create a History Channel documentary.
 * Though that may be simply because it would be cheaper then paying for a regular CGI sequence and most of the viewers probably couldn't tell the difference.
 * The last part of The Frozen Throne's Orc campaign has your four (or three) heroes take over a human city crawling with soldiers. But you're backed up by equally large amounts of soldiers from your side. Both sides fully embrace We Have Reserves philosophy on this one.
 * Zone of the Enders: the 2nd Runner featured the "Mars Melee," where the player and the hero from the first game had to protect the Redshirt Army from hundreds of enemies. It's by far the longest, most frantic battle in the whole game. You even get a special on-screen radar for this battle just to show you how many of the buggers you're up against.


 * Don't forget the level where you single-handedly take out an entire armada.
 * Halo Wars is this, start to finish. From the infantry level (massive mobs, a holdout in a Forerunner building, and one memorable cutscene of a Spartan squad holding a bridge against dozens of Elites) to combined-arms (the trailer is an actual battle that takes place, and has everything from marines fighting Elites to Warthogs to Banshees to Scorpions to much larger and scarier units), fights including multiple Scarabs, and a notable battle on top of a cruiser. It's safe to say that this game is made of this trope.

Survival Horror

 * Dead Rising effectively follows this trope from start to end, since an infinite supply of Zombies can--and will--spawn out of the thin air anywhere you aren't looking at the moment. Your first encounter with the Zombies, however, is specifically designed to show this off... a tidal-wave of undead flesh flowing endlessly through the front gates of the doomed mall, washing over anything and anyone who stands in its path.
 * The Wii version, not so much.
 * Resident Evil 4 has the Cabin Defense level, which has Leon and Louis hide Ashley and keep a horde of Ganados at bay until their numbers thin out so much they give up.

Tabletop Games

 * Near the end of Planescape: Torment the players get embroiled in a battle of the Blood War with both sides constantly respawning their troops. The PCs can get involved, or simply stand to one side and watch. Since it never stops, theoretically thousands upon thousands of enemies could be killed in this one battle. However, in an unusually-for-Black Isle linear and tightly-scripted game, this is one of the few areas where you have total freedom to earn large amounts of EXP, so throwing yourself into the free-for-all with wild abandon could be a good idea as well as fun.
 * In Throne of Bhaal, the Expansion Pack to ~Baldur's Gate~ 2, your party will charge an army trying to reach one of the bosses, and he'll stay away for a few minutes while you entertain yourself by slaughtering his minions.
 * One might argue that ~Baldur's Gate~ as a whole was full of this, with many areas featuring groups of enemies that inexplicably appear out of thin air the moment fog of war covers an area.
 * Icewind Dale, far more so than Baldur's Gate. Justified, since it was far less talking and far more fighting in the first place.

Third-Person Shooters

 * Played very much straight by Star Wars: Battlefront II. The second Kashyyyk mission in the Rise of the Empire campaign, appropriately named "A Line in the Sand", recreates the Separatists' siege of Kashyyyk from Revenge of the Sith, and you better believe it's All Up to You to get the Republic through this battle in one piece. After taking the command post on the beach and holding it for a while, you must fall back behind a huge sea wall to protect a Wookiee oil refinery on the other side. With limited reinforcements and a single tank at your disposal, you must Stand Your Ground and prevent the limitless swarms of droids from destroying the refinery for about three minutes. The sea wall itself is a great metal gate connected to two consoles on your side; if the CIS troops manage to destroy either console, the gate falls and their grenade-lobbing tanks can roll in and join the fun; if this happens, the voice-over of your commanding officer lets you know that all hell is about to break loose with the line, "They've breached the sea wall! Brace yourselves!" By means of consolation, if the refinery survives this hellish firefight, Yoda arrives Just in Time and the whole battle turns around, allowing you to drive off the CIS and claim victory.
 * The entirety of Battle Engine Aquila is this. It's about managing the enemy troops, flying around the battlefield to take out the right ones before they damage your forces' composition. So while you do have troops on your side, it's All Up to You.

Wide Open Sandbox

 * In Grand Theft Auto San Andreas, at the end of the Los Santos mission chain when CJ arrives late to a gang fight after discovering a horrible secret and has to kill waves of Ballas (some of them driving cars) while protecting his brother, with only the help of a few surviving gang members and some cars parked in a circle for cover.
 * Grand Theft Auto IV has a mission where a bank robbery goes awry and the enemies come in droves. Somewhat coupled with Escort Mission, only your allies are very useful in combat. Also a Fake Difficulty since there are only a few roadblocks that you really have to destroy, but there are so many of them it is entirely possible to lose your head and start engaging anyone in sight.
 * Red Dead Redemption, especially during the Mexican arc where you actually are helping to fight a war.
 * Saints Row: The Third's penultimate mission, "Three Way", features . Naturally, there's countless enemies that you're required to kill, not to mention the extras that randomly spawn around you every second or two due to double maxed notoriety.