[[caption-width-right:363: ''"Now's one of those times, it pays to be the strong, silent type"'' ]]

->''The year is 2552.''\\
''Humanity is at war with the alien alliance known as "The Covenant".''\\
''We are losing.''

''Halo 3: ODST'' is a ''Franchise/{{Halo}}'' GaidenGame released on September 22, 2009 as a [[MissionPackSequel stand-alone expansion]] of ''{{VideoGame/Halo 3}}''. Chronologically, ''ODST'' is concurrent with ''{{VideoGame/Halo 2}}'' - specifically, the game starts right at the end of ''Halo 2''[='s=] "Metropolis" level. At the beginning of the game, the Covenant have begun invading Earth, and are already occupying the city of New Mombasa. You take on the role of a newly transferred-in Orbital Drop Shock Trooper (known only as "The Rookie") who is trapped behind enemy lines after a botched drop and has to figure out what happened to the rest of his squad.

The gameplay is largely a throwback to ''VideoGame/HaloCombatEvolved'' with the less effective recharging stamina, the need to find health packs, no ability to go GunsAkimbo, and a pistol that is actually useful in its own way (''Halo 2'' and ''3'' were criticized in that regard). Uniquely for the series, the campaign is organized around a relatively open-world HubLevel, where it is up to the player to figure out which route they should take to their next objective, which is usually a clue about what happened to the rest of the squad; each time a clue is discovered, you will play through a flashback mission where you take on the role of one of the Rookie's squadmates.

The game also included a second disc that was comprised of the ''Halo 3'' multiplayer (no campaign) with all of the downloadable maps (including three that wouldn't be available otherwise for half a year after ''ODST''[='s=] release). In addition, it featured a new multiplayer mode called "Firefight" where you battled endless waves of Covenant coming after you.

While the game gained good reviews (particularly for its more intimate plot and atmosphere compared to other ''Halo'' games), some players have criticized its relatively short campaign.

Because of the issues that polluted the online modes of ''Halo: The Master Chief Collection'' on UsefulNotes/XboxOne, Creator/ThreeFourThreeIndustries promised that anyone who had played the game between its launch and December 18, 2014 would be eligible to download a full HD remaster of the ''Halo 3: ODST'' campaign at no charge. The remastered campaign was released on May 30, 2015[[note]]Unfortunately, this meant no Firefight multiplayer[[/note]]. For ineligible players, the campaign can be purchased as DownloadableContent for ''The Master Chief Collection'' at around six dollars.
!!''Tropers! We are green, and very, very mean!''
* AlternateEnding: Not quite the ending, but if you get all the Audio Files and make the Rookie more aware of what is going on than anyone else, a near-end cinematic will change. Specifically, the one [[spoiler:where you meet Vergil after it's been fused with an Engineer; instead of Dare telling you not to shoot it, you are the one that makes her not shoot the Engineer, after which you then basically tell it that it's safe to come down]].
* AnachronicOrder: The game starts with the squad dropping from orbit and the Rookie getting separated from everyone else. As he chases after them, he finds bits of discarded equipment which trigger playable {{Flashback}}s to his squadmates' adventures. It isn't until late in the game that everyone links back up.
* ApocalypticLog: The audio files scattered about the game, when put together, form something akin to a RadioDrama that describes the fall of New Mombasa from the point of view of one of the civilians in the conflict zone. It was written and developed by the same studio that Bungie employed to create ''ARG/ILoveBees'', and is something of a side story ''to'' a side story.
* ArbitraryMissionRestriction: The "Good Shepherd" achievement requires the player to complete the campaign without [[ShootTheMedicFirst killing any Engineers]], making things harder because Engineers give their teammates energy shields. Additionally, the "Vidmaster" challenge requires players to complete the final mission on Legendary difficulty without using any Warthogs or tanks, but to alleviate the challenge, the players are given [[FragileSpeedster Mongooses]] and near-infinite ammo rocket launchers.
* ArtificialBrilliance: You know the cop in the sub levels that fights alongside you[[spoiler:, and attempts to betray you, being a DirtyCop]]? Well, it turns out that this cop is one badass AI. I mean, he's been reported to actually Halo-jump ''out of the way'' of oncoming melee attacks, and is stated by prolific LetsPlay maker [=SSoPHKC=] to be "the greatest cop who ever lived".
* AsTheGoodBookSays: Dutch is known to throw this out on occasion. See "ReligiousBruiser" for a few quotes.
* BadassNormal: All of the ODST characters in the game are distinctly less powerful than Master Chief or any Spartan, but they prove to be resourceful in their own right. Buck [[spoiler: jumping on a Brute Chieftan's back and stabbing him in the neck repeatedly]] comes to mind.
* BenevolentAI: The New Mombasa Superintendent, aka "Vergil". It might be a damaged "dumb" AI[[note]]"Dumb" is used here in the sense that its learning capabilities are far inferior to those of a "Smart" AI like Cortana[[/note]], but it's nothing but helpful to you. The audio logs reveal that it was also programmed to look after Sadie, its caretaker's daughter, which it does dutifully.
* BoomHeadshot: There are two Achievements for shooting enemies in the head. One is called "Boom, Headshot".
* CanonImmigrant: The game is the first ''Halo'' FPS to have Covenant Engineers (or "Huragok" in the Covenant's own spoken language). Bungie had been trying to work them into the gameplay since ''VideoGame/HaloCombatEvolved'', but didn't manage to do so until ''ODST''. The Engineers have always had a presence in the ''Halo'' ExpandedUniverse from the [[Literature/HaloTheFallOfReach very first book]] onward, but it took the design team a while before they could figure out a way to incorporate what is essentially a non-combatant Covenant race into the combat-heavy FirstPersonShooter series in a meaningful way.
* TheCasanova: [[InformedAbility Romeo claims to be one]], hence his moniker. Given his disposition, it seems like he might play to the AllGirlsWantBadBoys appeal.
* ContinuityNod: Just before the Covenant carrier jumps out of the city, you can see a little black speck approach its starboard side. That speck is the ''[[VideoGame/{{Halo 2}} In Amber Clad]]''.
* CriticalAnnoyance: If you take damage, your player character will grant you the pleasure of obnoxiously grunting and panting while their stamina regenerates. If their underlying health bar takes a hit, you'll be granted the further pleasure of a constant beeping sound until you find a health pack.
* DirtyCop:
** The audio logs have Kinsler, New Mombasa's Police Commissioner. He tries to kill Sadie, arranges her father's death, and then hijacks a subway car to get away safely while hundreds of people are trying to get in as well. Luckily [[KarmicDeath karma catches up with him]] in the end, and he's literally ripped to pieces when said hundreds of people storm the train.
** In the game itself, [[spoiler:the officer in "Data Hive" is revealed to be this if you've collected 29 audio logs. In fact, the reason he's there to begin with is to confirm for Kinsler that Sadie's father is indeed dead]].
* DisproportionateRetribution: In the audio logs, when Sadie and her police friend get to the NMPD building, they meet an ex-cop who, seeing as everyone is going to hell soon enough, has decided to send a few of his "[[TermsOfEndangerment old buddies]]" on their way himself.
-->'''Marshal:''' Remember how many times I asked you not to use my half-and-half? And remember how many times you... didn't listen?\\
'''Jim:''' Wha- You did ''this?''\\
'''Marshal:''' You should have stayed in the elevator, Jim... [[PunctuatedForEmphasis I wrote! -bang- My name! -bang- Right there on the carton! -bang-]]\\
'''Mike:''' Come on, Sadie, let's go...\\
'''Marshal:''' According to his department, I have issues with anger management!" -click- "If I were you... I'd stay right where you were.
* DownerBeginning: The Rookie wakes up in the middle of the occupation of New Mombasa by the Covenant.
* DynamicLoading: The ''Halo'' engine has always had this in the "fixed path" variation, but this title plays with it a lot more in the New Mombasa streets that the Rookie explores. Downtown New Mombasa is divided up into several hexagonal blocks by walls (justified in-universe as being mandatory safety measures to minimize damage in case there is a serious accident on the space elevator) with doors closing off the joining streets to stall the Covenant. The Rookie can trigger a manual override of each door, opening it to let himself through. This is intended to slow the player down enough to let the next section of the city load into memory.
* EscortMission: Towards the end, [[spoiler:you have to escort an Engineer defector to safety. It has enough health to not be a hassle (especially after it commanders an Olifant truck) and gives you shields if you stay nearby]].
* {{Expy}}: Buck has been described by some reviewers as "[[Series/{{Firefly}} Mal Reynolds]] [[XMeetsY as a]] SpaceMarine". They usually add that this is not necessarily a bad thing. He's even portrayed by [[Creator/NathanFillion the same actor]]!
* FakeStatic: In the audio logs, Sadie tries it on her father, only for him to point out it's a video feed.
* FilmNoir: A huge source of inspiration for the game, [[WordOfGod as stated by Bungie]]. The influence can be felt in the game in the way the Rookie interacts with the world by seeking out little clues to give him a picture of what happened when trying to locate his squad, the sense of wandering alone through a rainy city at night, and the [[MoodMotif lonely saxophone solos]] in the music.
* FireForgedFriends: The entire ODST squad counts, but specifically the Rookie, Buck, and Dare.
* ForegoneConclusion: Everyone who has played ''Halo 2'' and ''Halo 3'' already knows why the Covenant attacked New Mombasa and what they are looking for, but the cast is kept in the dark the entire game.
* {{Foreshadowing}}:
** Bungie got clever with this. First, watch the "Desperate Measures" video, paying close attention to the audio starting at around the 2:24 mark. Then, once that's done, go play the final campaign level, "Coastal Highway". And here you thought Buck's line in the video was just hyperbole, didn't you? [[spoiler:Specifically, Buck notes that the Superintendent could "commander the city's garbage trucks if we need 'em". Guess what ends up happening?]]
** Buck is described in-game as being so good that he could be a Spartan. Come ''VideoGame/Halo5Guardians''...
* GentleGiant: Jonas from the audio logs. 6'10, 500 pounds, and is very soft-spoken, [[BewareTheNiceOnes even when threatening someone]]:
-->'''Angry Driver:''' You put your cleaver through the hood of my car!\\
'''Jonas:''' Oh, a thousand pardons. But it was either that, or smash your windshield, pull you out, and make you into kebabs.\\
'''Angry Driver:''' What?! No! No-no! Hey wait!\\
'''Jonas:''' Then please. Stop honking your horn. It frightens the children.
* TheGreatestStoryNeverTold: Compared to the plots of the Master Chief games.
* HeroicMime: The Rookie, while making the occasional grunt when throwing a grenade, or crying out in pain when shot, never says a single word the entire game.
* HeroicSacrifice: Implied with Jonas in the audio logs. He refuses to leave New Mombasa because he would take up too much room on any evacuating vehicle, and flatly insists his life isn't worth five others.
* HostageSituation: Happens twice in the audio logs.
* HubLevel: "Mombasa Streets", which features the Rookie running around finding beacons that unlock other levels, depicted as flashbacks. Playing through one level unlocks the next one, but you can't go back and replay old levels. "Mombasa Streets" also has plenty of enemies, plus terminals which give backstory to New Mombasa.
* HumansAreBastards[=/=]HumansAreMorons: The audio logs paint a rather unflattering picture of New Mombasa's citizenry, most of whom are depicted as various mixes of greedy, selfish, corrupt, and TooDumbToLive.
* InkSuitActor: Both Creator/NathanFillion's and Creator/TriciaHelfer's respective characters of Buck and Dare are modeled after their likenesses.
* ItsRainingMen: As expected for Orbital Drop Shock Troopers. The player is treated to a first-person depiction of an ODST drop operation in the game's opening.
* {{Jerkass}}: Romeo is a mild example. [[WordOfGod Described by Joe Staten as]] "a bit of a dick", his profile states that he has had some discipline infractions that, in less desperate times, could have gotten him discharged. But given the state of the war, [[BunnyEarsLawyer his skills are too valuable to simply let go]].
* LateToTheTragedy: The Rookie spends most of the game playing catch-up.
* LivingMacGuffin: It turns out that your squad's actual mission is to recover [[spoiler:an Engineer who defected from the Covenant]]. [[spoiler:Said Engineer]] also serves this role in the audio logs; Sadie comes to value it because [[spoiler:it downloaded Virgil, the last thing left of her father's work]], while Kinsler wants to capture it so he can be branded a war hero.
* LonelyPianoPiece: One of the common forms of music during the Rookie's segments, along with an occasional slow saxophone solo, to fit the game's contemplative pace and theme of isolation.
* LowerDeckEpisode: The game is a more personal story of a squad of [[EliteMooks elite]] {{redshirt}}s deployed for a single mission that spans less than half a day of narrative time, in contrast to the series's usual stories of a SuperSoldier who alter the course of the war, fights an EldritchAbomination, and prevents genocide on a galactic scale.
* MissionControl: Played with by the Superintendent/Vergil. Its communication capabilities are incredibly limited, so it has to resort to [[OnceForYesTwiceForNo manipulating electronic signs and playing pre-recorded audio phrases]] to guide the Rookie through the city. It will also highlight areas of interest on your map and try to get your attention if you're near an audio file.
* MultiMookMelee: Several moments in the campaign, most notably the rooftop battle at the end of "NMPD HQ". Additionally, Firefight revolves entirely around this trope.
* {{Nerf}}:
** Being a puny human instead of a Spartan supersoldier, your melee attacks do noticeably less damage than in ''Halo 3'' proper. Most noticeably, they are no longer a one-hit-kill against enemies like Grunts and Jackals.
** Because Brutes' energy shields now resist human projectile weapons, guns like the assault rifle are noticeably less effective.
** The assault rifle itself has been nerfed so that the game's signature SMG is more effective. Other than against vehicles, there is no situation in which the AR would be more useful than the SMG.
* OnceForYesTwiceForNo: Vergil can only communicate via pre-recorded audio city notices and traffic signs. For example, when attempting to ask marines to not blow up a bridge, it initially asks them to "Keep It Clean, Respect Public Property", but when faced with the eventuality that the Covenant would soon be accessing its datacenter, the AI releases the bridge controls and ironically responds "Bridge Toll Accepted, Have a Pleasant Trip".
* OpeningScroll: Notably the only ''Halo'' game to do this.
* ProductionForeshadowing: Ever saw [[http://www.destinypedia.com/File:Destiny_Awaits.jpg this poster]] lying around the city? Well, ThatsNoMoon, [[{{VideoGame/Destiny}} that's The Traveller]].
* ReligiousBruiser: Dutch.
** After doing a jump in a Warthog/Ghost/Chopper and crash-landing:
--> '''Dutch:''' Uh, [[{{God}} Lord]]? I didn't train to be a pilot. Tell me I don't have any more ''flying'' to do today.\\
''(Aerial drone crashes into a nearby statue)''\\
'''Dutch:''' So, was that a yes or a no?\\
''(Warthog/Ghost/Chopper explodes)''\\
'''Dutch:''' Amen.
** Later:
-->'''Dutch:''' Well, [[AsTheGoodBookSays like the good book says]], payback's a bitch. \\
'''Mickey:''' I don't think it actually says that, Dutch. \\
'''Dutch:''' I'm paraphrasin', ya heathen!
* {{Retcon}}: The game radically alters the look and layout of New Mombasa from the way it was shown in ''Halo 2''. The space elevator is now on its own manmade island instead of in the city center, the buildings of downtown are more futuristic and imposing, and the massive suspension bridge that Master Chief crossed in ''Halo 2'' is nowhere to be seen.
* RuleOfSymbolism: Parts of the game are symbolic of Dante's ''Literature/TheDivineComedy''. Two of the biggies:
** Vergil: Named after Dante's companion, it is the Rookie's guide for most of the game, and helps you figure out the story of what happened when you were knocked out in your pod.
** If you collect all of the Audio Files, you can see they are organized into "Circles" and refer to the [[SevenDeadlySins sins from the Inferno]]. [[http://www.bungie.net/Forums/posts.aspx?postID=37475960 More details here.]]
** Then there's Dare. It's suspiciously like a ''{{Theatre/Godspell}}'' reference, considering her role in the game.
* SceneryGorn: Being a battlefield, nearly all of New Mombasa. During the nighttime stages where you play as the Rookie, the city, despite remaining semi-functional while in lockdown, is littered with all of the signs of the war that now rages there.
* SergeantRock: Buck is a near-textbook example of the archetype. He has served in the [=ODSTs=] for a long time with a proven success record. The game even says, "if he were any better, he'd be a [[SuperSoldier Spartan]]." [[spoiler:[[HilariousInHindsight Buck and the rest of his squad (save Dutch and the Rookie) eventually become Spartan-[=IV=]s after the war.]]]]
* ShootTheMedicFirst: Engineers give their allies overshields. The shields dissipate when the Engineer is killed, so it is in your best interest to aim for them first, making the rest a bit easier. There are achievements both for doing this and not doing it in the hub level.
* ShoutOut:
** The game shares some themes with ''VideoGame/PathwaysIntoDarkness'' and ''VideoGame/{{Marathon}}'':
*** You're a soldier who gets knocked out on his drop and wakes up hours later, presumed dead by your squad. You must discover what happened via interacting with inanimate objects and dead bodies to find out what happened to your squad. Your mission involves an extremely powerful being who is manipulating events above while dealing with hostile non-humans.
*** In some buildings there are simplified [[VideoGame/{{Marathon}} Thoth logos]] on the walls.
*** The Engineers are presented in this game the same way as the S'pht in ''Marathon''.
** Vergil: It is your only companion (as the Rookie) for most of the game. It guides you and helps you figure out the story of what happened when you were asleep in your pod; this is very similar to the original Virgil from ''Literature/TheDivineComedy''. Other references to ''The Divine Comedy'' also play a large part of the game. If you collect all of the Audio Files, you can see [[http://www.halopedia.org/Audio_Log#Trivia they are organized into "Circles"]] and refer to the [[SevenDeadlySins sins from the Inferno]].
** Dare seems to be a reference to the Biblical pebble.
** The entire "Drop Pod" concept comes from ''Literature/StarshipTroopers''.
* SpaceTrucker: [[AllThereInTheManual Mentioned in Dutch's background]]. He drove cargo trucks on {{UsefulNotes/Mars}} in order to put himself through college, where he majored in [[ReligiousBruiser religion and philosophy]].
* SplitPersonalityMerge: [[spoiler:Vergil ends up being downloaded into an Engineer.]]
* StrictlyProfessionalRelationship: Captain Dare was once in a relationship with Sergeant Buck, but broke it off because of [[TheSpook her work with ONI]]. She intends to keep things professional when the two are put in the same unit again, but he's still openly angry at her, and she eventually starts letting her affection show through. [[spoiler:They end up hooking back together by the end.]]
* SupportingProtagonist: The Rookie. His story comprises the MythArc of the game but he doesn't do much to help the mission until the end, being knocked out and all. It's more the story of the other [=ODSTs=], especially Buck and Dare.
* SWATTeam: One of these makes a brief appearance in "Sadie's Story".
* ThreeVolleyFlinch: In the trailer ''[[https://www.youtube.com/watch?v=w5Dc2At5_AE The Life]]'', a funeral is held for a deceased [[ItsRainingMen Orbital Drop Shock Trooper]]. One of his relatives, Tarkov, flinches at the three-volley salute, but the next scene shows him enlisting for the [=ODSTs=].
* ToneShift: This game is intentionally tonally different than the other entries in the ''Halo'' series. Aside from the shorter length, it has a more focused narrative seen from several more points of view, along with a quieter, more contemplative pace. Large sections of the game are low-intensity affairs where the player can explore at will, with minimal exposition other than what they can piece together from the environment, which are in turn punctuated with linear sections of more intense action and direct story-telling.
* TookALevelInBadass: Brutes are noticeably tougher in ''ODST'' than they were in ''Halo 3''. This is mostly because their shields now take half damage from human projectile weapons, allowing them to soak noticeably more bullets before going down (the plasma rifle or noob combo still owns them, though).
* UnderratedAndOverleveled: If one stops to think about it, all the characters are this. The main ''Halo'' franchise focuses on a badass SuperSoldier who was picked from the best of the best, trained from childhood, underwent expensive and dangerous procedures to enhance his physical and mental abilities, and given PoweredArmor equipped with shield technology stolen from the enemy. The characters in this game are...well trained soldiers. They ''are'' implied to be incredibly skilled even when compared to the rest of the highly elite [[ItsRainingMen ODSTs]], but they are ''not'' super soldiers. However, the game engine is the same as ''Halo 3'', meaning the ODST soldiers are just as powerful as Master Chief. They lose the shields (but replace them with a stamina system that makes them nearly as durable), and they can't punch through tanks like the Chief, but that's about the only difference. In contrast, ODST [=NPCs=] in the other games are nothing to write home about.
** Heck, there's one area where the [=ODST=]s even ''outperform'' Chief, at least until ''{{VideoGame/Halo 4}}''. In ''3'', Chief is slowed considerably while wielding a dismounted turret, but in ''ODST'', none of the playable characters suffer this speed reduction.
* UniqueEnemy:
** If you've collected 29 audio logs, [[spoiler:the NMPD officer in "Data Hive" becomes this, despite him having previously been your ally for much of the level]].
** The [[EliteMooks Drone Leaders]], which are golden and have energy shields.
->''Bam, said the lady.''