* AlternateCharacterInterpretation:
** One of the more prominent theories in the fandom's early days was that Cortana had deliberately led the ''Pillar of Autumn'' to Installation 04 for her own purposes, and was at best very selective about what information she shared with Master Chief; this was based on players who came in directly from ''Marathon'' expecting her to still be characterized as she was in "The Cortana Letters", and her statement to Keyes about making a "blind jump" being contradicted by ''The Fall of Reach'', where her decision was shown to be at least partially informed.
** With the benefit of hindsight, when 343 Guilty Spark explains the true purpose of Halo and seems confused by how Master Chief couldn't have known about it, is he just putting on an act as a result of his insanity, or, as he does immediately after when he comments about the "last time" he and Chief talked, is he [[spoiler:confusing him for the [=IsoDidact=]]]? One interpretation leans into his rampancy, while the other leans into his memory of someone who [[spoiler:has fired the Halos before, meaning he should know what they do already]].
* AntiClimaxBoss: Aside from not having a "final boss" to fight, the game's ending EscapeSequence is actually fairly easy, assuming you're already well-accustomed to the Warthog's awkward driving physics. Even if you crash a few times, you can still complete the run with minutes to spare, and [=Legendary=] only bumps down the timer one minute.
* BestLevelEver:
** The aptly-named second level, Silent Cartographer, Assault on the Control Room and The Maw are recognized as some of the most iconic levels in the series.
** When it comes to multiplayer maps, Blood Gulch is this without a doubt. ''WebAnimation/RedVsBlue'' aside, its layout makes it the perfect level to have hectic Big Team Battles.
* BreatherLevel: The first half of 343 Guilty Spark focuses more on atmosphere than being challenging. The only enemies faced are small groups of Grunts and Jackals who will even ignore you occasionally. Of course, [[GenreShift this all changes once you discover the Flood]]. Even then, however, the Flood and their various gimmicks[[note]]Infection Forms, Elite Combat Forms, Human Combat Forms, Flood with weaponry[[/note]] are gradually introduced to the player to give them time to adjust to fighting this new enemy until they finally get out of the compound.
* ComplacentGamingSyndrome:
** The PC port of ''Halo: Combat Evolved'' has a demo that houses servers featuring 24/7 max vehicle 16-player CTF matches on Blood Gulch, and nearly nothing else; in fairness, Blood Gulch is the only map available in the demo and until the port of ''The Master Chief Collection'', this demo was basically the only way to still get the game on PC. Organized 4v4 or 2v2 games are a rarity if they ever existed at all.
** In general, ''Combat Evolved'' multiplayer revolved around the original [=M6D=] Pistol, which isn't unusual as mid-range combat makes a large bulk of combat in the ''Halo'' franchise; the precision weapon is often considered the UtilityWeapon. The pistol is simply most infamous for the role [[PunchPackingPistol because it's a pistol]] instead of the later standard scoped rifle.
* CommonKnowledge: Contrary to popular opinion, not only was this game not the first video game (or FPS, for that matter) to feature regenerating health, but it doesn't even feature regenerating health at all; the player's ''shield'' regenerates after a certain amount of time, but health is a static and separate mechanic, and actual regenerating health would only be introduced in the next game. The first game to ever feature regenerating health was actually ''VideoGame/PunchOut'', while ''VideoGame/{{Hydlide}}'' was the first game to feature it in the "take cover for a few seconds" manner that eventually became commonplace in [=FPS's=].
* DemonicSpiders:
** Flood Combat Forms armed with Rocket Launchers are an endless source of cheap death. Insane reflexes plus sniper rifle accuracy plus typically spawning in enclosed spaces or areas where vehicles are expected to be used equals a bad time for all involved.
** Although Hunters are easy on foot, they can become a problem while driving the Scorpion on "Assault on the Control Room". Especially while you're dealing with other stuff such as Wraiths and Ghosts.
** The remaster actually turns Stealth Elites into this; the graphics make their Active Camouflage a lot more effective, partly due to the brightness of the newer aesthetics, and ''especially'' the ones that wield Energy Swords, as their less lightsaber-like glow is tremendously more difficult to spot.
* DisappointingLastLevel: For some, the last three levels were this because of extensive BackTracking (the final third of the game is essentially the entire first half of it in reverse and with the Flood and Sentinels added). Many still consider "Two Betrayals" and "The Maw" among the best levels.
* EnsembleDarkhorse:
** The fan-named Thirsty Grunt, a grunt encountered as an EasterEgg near the end of the final level as the sole survivor among several Flood corpses. He doesn't attack the player and instead comments on how the battle made him work up "a big, grunty thirst!" Subsequent games would include similar hidden grunts as a tribute.
** [[AcePilot Foehammer]] has quite a large fanbase despite her never actually physically appearing onscreen, owing to her status as the MauveShirt pilot who delivers your vehicles and reinforcements, drops you off, and picks you up throughout the story. The fact that she winds up surviving ''the entire campaign'' even as the other Marine forces are annihilated by the Covenant and the Flood [[spoiler:only to die [[HopeSpot right as she's about to pull]] a GunshipRescue in the final level]] only heightened her appeal.
** Sergeant Johnson; it's easy to forget that he was simply a RecurringExtra in this game as a generic Marine sergeant who was given a bit of extra focus thanks to his role in the intro cutscene, [[spoiler:accompanying Captain Keyes on his ill-fated weapons cache expedition]], and for being the focus of the secret Legendary ending. That, plus his memorably hammy voice acting and SergeantRock personality stemming from being an obvious [[Film/{{Aliens}} Sergeant Al Apone]] homage, made him an immediate BreakoutCharacter who was promoted to the main cast in the sequel.
* {{Fanon}}: The second SPARTAN in campaign co-op is generally believed to be either [[VideoGame/HaloReach Noble Six]] (had he escaped Reach), or [[https://www.halopedia.org/Linda-058 Linda-058]] (who canonically was in cryo on board the ''Pillar of Autumn'' during the game). The latter is probably the most accepted by people who pay attention to the Expanded Universe, particularly after her cameo in the remaster.
* GameBreaker:
** The PunchPackingPistol, at least, for many people. Its perfect-kill ratio is three shots, and it regularly keeps the power weapons (namely the Sniper Rifle) in check. The Magnum got {{nerf}}ed ''heavily'' in the sequels. ''Videogame/Halo2'''s Magnum ([=M6C=]) had a much faster [=RoF=] (Rate of Fire), but it took ''13'' bullets (one whole magazine and one bullet from the next) to kill a player. The [=M6G=] in ''Videogame/Halo3'' added some much-needed power back to the Pistol, but reduced the magazine to 8 shots and had the slowest [=RoF=] out of them all. It wouldn't be until ''Videogame/Halo3ODST'' that the Magnum would regain respectable power, [=RoF=] ''and'' the ability to scope, while remaining balanced.
** The [[InfiniteAmmo Bandanna skull]] from Anniversary tears the game to ribbons. While there's the obvious problem with shotguns, sniper rifles and rocket launchers, the real game-breaker is infinite grenades. In a game filled to the brim with tight spaces and walkways, the player can chuck grenades like mad with little need to aim. Add Grunt Funeral for extra power. Most of the achievements are still attainable with it too. In fact, you can use it to make one of the achievements (which requires you to beat a level on Heroic with three skulls on) a cinch.
** The PC/Mac port made the Banshee available in Multiplayer, with its Fuel Rod Gun intact. The latter is what particularly makes it a GameBreaker, due to its unlimited ammo, being fired from a high vantage point, flipping ground vehicles with ease, and just plain wasting infantry. It does have a somewhat slow rate of fire, but one well-aimed shot is generally all it takes to ruin someone's day. The lack of counterplay was the most damning, as the Banshees were originally designed to be controlled by the AI and move in predictable patterns; only tanks are generally very effective against them. Rockets are too slow to properly lead with at anything other than close range and tend to result in you getting splattered by the empty Banshee if you managed to kill the pilot.
* GenreTurningPoint: ''Halo'' is widely considered to have modernized the FPS genre, influencing pretty much every shooter made after it. It was so influential that contemporary shooters were often labelled as "''Halo'' killers", being seen as direct competition to it.
* GoddamnedBats:
** Flood infection forms are almost completely harmless as long as your shields are up, but are hard to hit, and have the annoying tendency to jump in your face as soon as they get close.
** Jackals, whose shields block them from easy kills. With the exception of explosives and melee attacks, the best method of taking them down is precise shots to their exposed arms.
* GoodBadBugs: A double-edged sword with [[RammingAlwaysWorks vehicle collisions]]. The devs couldn't figure out how to actually get roadkilling enemies to work properly before release, so they ultimately made a compromise: if a vehicle is moving, it's a OneHitKill if a player or NPC so much as touches the paintjob. This can be very exploitable in select cases of the campaign -- and lead to UnfriendlyFire galore the moment a teammate decides to hop out of a still-moving Warthog and meets CriticalExistenceFailure because their ass clipped the side.
* HarsherInHindsight: Cortana's "This war has enough dead heroes" retort at Keyes gains a ''lot'' of gravitas after playing ''VideoGame/HaloReach'' (or reading the novel it was based on), [[spoiler:and even more so after Cortana's FaceHeelTurn in ''VideoGame/Halo5Guardians'']].
* SugarWiki/HeartwarmingMoments: Or Funny, but [[spoiler: the ending on Legendary campaign feels like this]].
--> [[spoiler:'''Johnson:''' This is it, baby, hold me.]]\\
[[spoiler:''[he and the Covenant Elite hug each other as Halo explodes]'']]
* HilariousInHindsight:
** [[ExpandedUniverse Considering just how much the EU expanded]], [[KillerApp and how far the games went]], the final words of the campaign:
--->'''Cortana''': [[TemptingFate Halo. It's finished]].\\
'''Master Chief''': [[UnderStatement No, I think we're just getting started]].
** A likely intentional example of {{Foreshadowing}} is Sergeant Johnson's speech at the start of the game on Legendary difficulty, where he states that he doesn't care whether or not Halo is either "God's own anti-son-of-a-bitch machine" or "a giant hula hoop". It turns out that the former is pretty much spot on.
* IronWoobie: Guilty Spark, according to the Terminals. He waited for 100,000 years alone on his ring, refusing to leave despite his loneliness and risk that the Flood might break out or that his ring might fall into disarray. [[spoiler:He went crazy]].
* ItWasHisSled: With the Flood's appearance in the level "343 Guilty Spark", the Covenant suddenly goes from being "the big-time threat" to "a secondary nuisance." It was a massive twist at the time, but now it's one of the game's more notable moments. And the Flood have such a central role in the lore of ''Halo'' that it's hard ''not'' to talk about their appearance here.
* LadyMondegreen: ''Combat Evolved'' introduced to us "Dustin Echoes", after a line where Cortana responds that all that's left is "just dust and echoes." {{Creator/Bungie}} even joked about this in their commentary for the cutscenes!
* MemeticMutation:
** "Wort wort wort!" [[labelnote:Explanation]]One of the the voice lines that Elites may shout when they notice the Chief. Out of all the alien nonsense lines it's the most iconic and quoted.[[/labelnote]]
** "This cave is not a natural formation."[[labelnote:Explanation:]]Cortana [[CaptainObvious describing]] a clearly metallic Forerunner tunnel to the Master Chief in "Halo". According to WordOfGod the dialogue [[TheArtifact was from when]] the tunnels looked more natural.[[/labelnote]]
** Dustin Echoes, the Ultimate Marine[[note]]Another meme relating to Cortana's dialogue, this time during the very end of the game. When Master Chief asks if there were any other survivors of Installation 4's destruction, Cortana replies with "Just 'dust and echoes'", as a poetic way to say that everyone but her and Chief died. Due to audio quality issues and a lack of subtitles for the time, however, people took this to say that there was exactly one survivor, a Marine named Dustin Echoes who somehow survived ''planetary annihilation'' no worse for wear. Cue speculation on how cool Dustin must be and what kind of adventures he gets into.[[/note]]
* PortingDisaster:
** It's somewhat debated over ''how'' much the Windows port averts this; graphics, textures and level geometry were downgraded, particularly in bumpmapping, which was extensively used to give surfaces detail, being broken in the port (so that it only actually shows up if you shine your flashlight on it), the Plasma weapons weren't capable of stun-locking players as effectively, and there's no co-op function. However, it was the first version of the game to include online multiplayer, the later release of a "''Custom Edition''" added proper modding support, and it was very well supported by Bungie and Gearbox. The final patch, 1.10, came out in 2014, 11 years after launch and 4 years after Bungie stepped away from the series. The Mac OS X port, however, had far worse performance, was extremely crash-prone and had horrible network code.
** ''Anniversary'' was built on top of the PC port, and carried over many of its graphical downgrades when you are using the classic graphics. Thankfully, this was addressed in ''The Master Chief Collection'', where the classic graphics were reworked in the Season 7 update to make it much closer to the Xbox original.
* RescuedFromTheScrappyHeap: While still a largely despised character, 343 Guilty Spark could be perceived as something of a ''tragic'' character, thanks to the Terminals of ''Anniversary''. ''Halo: Renegades'' also cements this with his [[spoiler:redemption arc.]]
* TheScrappy: 343 Guilty Spark for leading you through "[[ThatOneLevel The Library]]", including a bit where he has to go open a door and seals the one you just came through to make fighting the ensuing Flood far more difficult, then for betraying you to activate Halo. Many people were glad that [[spoiler:you got to kill him at the end of ''Halo 3''.]]
* ScrappyWeapon:
** The Assault Rifle. This is partly based on the fact that its name implies an entirely different method of operation than what it actually gets. While it does have its upsides - generous ammo capacity (60 rounds per mag, 600 in total) with an extremely fast rate of fire letting it shred through shields despite bullet-firing weapons' poor performance against them, having a really fast QuickMelee animation, and the fact that switching to it lets players in MP with invisibility become fully invisible instantly (compared to the several seconds to fade out when using scoped or other heavy weapons) - much of these positives are left unrecognized, as most players still hate it because of its incredibly wide shot spread and [[ArbitraryGunPower anaemic damage per shot]]. It quickly regains usefulness once the Flood shows up, however, being one of the more efficient methods of clearing out Infection Form swarms next to explosives.
** The Needler in the multiplayer. Think of it as the Gauntlet in ''VideoGame/QuakeIIIArena''. While the Needler in the Campaign is a whole different weapon, since its slow projectiles are still able to connect with an Elite's body, emptying an entire magazine at a player who makes a minimal effort to strafe will result in none of the needles hitting their target.
* SpiritualAdaptation: The best adaptation of ''Film/{{Aliens}}'' ever made. There's a reason that Halopedia has a whole page just for listing [[https://www.halopedia.org/List_of_references_to_Aliens_in_the_Halo_series Alien references]], and that almost all of these references show up in the first game.
* SpiritualSuccessor: To the ''VideoGame/{{Marathon}}'' trilogy. Pretty much every single bit of human tech, signage or terminology (as well as the related gameplay mechanics), except for the appearance and gameplay functionality of the MJOLNIR armour, was lifted wholesale from ''Marathon'' and into ''Halo''.
* TaintedByThePreview: Anyone who played the ''Halo'' build of E3 2001 stated that the game was unbelievably hot garbage, with abysmal frame rates, uninspiring graphics, and just an overall ObviousBeta. No one expected ''Halo'' to be anything more than ''at best'' average after trying the demo.
* TearJerker: The death of [[spoiler:Foehammer]]. Anniversary adds [[spoiler:the terminal on "Keyes"]].
* ThatOneAchievement: ''Anniversary'' adds several difficult Achievements, but the worst would have to be "Speed Reader". It involves completing [[ThatOneLevel The Library]] on [[HarderThanHard Legendary in 30 minutes or less]]. Victory, thy name is [[BottomlessMagazines Bandanna]].
* ThatOneLevel:
** The indoor segments of "Assault on the Control Room" have you go through several long identical-looking hallways. On harder difficulties, conserving ammo can be a problem. This is somewhat remedied by SequenceBreaking (via jumping on the windows on the bridges which connect to said indoor segments).
** The Library is [[MarathonLevel long, repetitive,]] full of Flood that love to spawn in waves to delay your progress, dark and you can lose your way easily. And you have to deal with the expository ramblings of [[TheScrappy Guilty Spark]] for the whole level. [[LampshadeHanging This is practically lampshaded in the novelization.]] It's also the first level to introduce Flood with Rocket Launchers, which can be a ''very'' quick and nasty death.
** The indoor segments in [=AotCR=] make a return in [[LevelinReverse "Two Betrayals"]], with the Flood this time. While you can be fine if you know how to read the floor arrows, what takes the cake in "Two Betrayals" is Pulse Generator #2. Up to ''four'' Rocket Launcher-wielding combat forms can be among the twenty or more that jump you just as you're making the required shield overload. The nearest health pack is all the way at the bottom of the canyon outside, so have fun reverting if you're at anything less than full health. The level also features a particularly nasty battle near the end, where the game almost literally throws ''everything'' it has at you. Rocket Flood, Stealth Elites, Turret Grunts, and ''two'' Wraiths are the main nuisances, and that doesn't even take into account the veritable army of lesser enemies duking it out. Letting the two factions wear each other out won't help much, as the Covenant will [[CurbStompBattle curb-stomp]] the Flood before an entire miniature army comes at you.
** "Keyes" suffers from the same problems as ''The Library'' regarding how the Flood like to spawn. At least one section has endless waves of Carrier Forms emerging from a coolant pool that happens to be between you and the path forward, and once you get back on the ''Truth and Reconciliation'' the corridors are ''choked'' with Flood that race up from the next sections and force you to kill them all at once.
** The last section of "The Maw" requires you to drive a Warthog along an obstacle course against the clock. If you find the Warthog hard to control, this is rather annoying. And when you finally reach the target, [[spoiler: the pickup transport for which you have been waiting for crashes, and you have to reach another target, within the original time limit, which may result in having to start all over again.]] Which is also rather annoying. That said, it can be made a lot easier when you realize that the clock stops while the shuttle takes its dive, but you're not obligated to stand still, so you can get a few free seconds of extra driving time if you don't stop to watch.
** Multiplayer has Chiron TL-34. The sheer number of teleporters (which would be phased out by ''Halo 3'' due to camping concerns) led to a super-confusing map that has virtually no gameplay flow. Bungie acknowledged this and teased a "Chiron TL-35" during ''Halo 3'' as a joke.
* TheyChangedItNowItSucks: ''Anniversary'''s graphics were criticized for greatly deviating from the original graphics, marking a stark contrast to the tone the original was going for in some areas. This is most apparent in "343 Guilty Spark", where the dark, foreboding swamp that foreshadowed the level's twist of the Flood is now heavily lit up.
* WhatDoYouMeanItsNotPolitical:
** A lot of people saw the premise of ScaryDogmaticAliens starting a war against heroic Eaglelandish marines as typical TurnOfTheMillennium propaganda about UsefulNotes/TheWarOnTerror. Bungie countered this by pointing out that [[ProductionLeadTime the overwhelming majority of the game's development occurred]] ''before'' 9/11. However, note that no references to the Covenant being religious zealots actually show up in ''Combat Evolved'' aside from lines in the manual and a couple of offhand lines in-game that easily could've been added late in the development process. Also note that ''Literature/HaloTheFallOfReach'', which is responsible for much of the universe's backstory, was written in around ''seven'' weeks (reported as Eric Nylund's shortest deadline). That's from a full week after 9/11, to the day the novel was released. ''Halo 2'' muddies this even further, as it dives deeper into the Covenant viewpoint and amalgamates them into more of a hybrid Catholic/extremist Islam-style theocracy.
** After the end of [[UsefulNotes/TheApartheidEra Apartheid]] in South Africa, the new multi-racial government set up the [[http://en.wikipedia.org/wiki/Truth_and_Reconciliation_Commission_%28South_Africa%29 Truth and Reconciliation Commission]] to investigate human rights abuses under the old regime. In Halo, the multi-racial Covenant have a ship called the ''Truth And Reconciliation.'' Draw your own conclusions.
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