[[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 [[MissionPackSequel stand-alone expansion]] of ''{{VideoGame/Halo 3}}''. Chronologically ODST is concurrent with certain events of ''{{VideoGame/Halo 2}}'' - specifically, the game starts right at the end of the "Metropolis" level of ''Halo 2''. During that game, the Covenant had started a full invasion of Earth and occupied the city of New Mombasa. You take on the role of a rookie Orbital Drop Shock Trooper who is trapped behind enemy lines during a drop and it plays out as a GaidenGame story.

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 as a result the use of a pistol that is actually useful in its own way (''Halo 2'' and ''3'' were criticized in that regard). While gaining good reviews, some players have criticized a relatively short campaign.

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.

Because of issues that polluted the online modes of ''Halo: The Master Chief Collection'' on UsefulNotes/XboxOne, 343 Industries 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 a near-end cinematic will change a situation if you get all the Audio Files and make the Rookie more aware of what is going on than anyone else.
** [[spoiler:This, in fact, changes the cinematic when you meet Vergil. Instead of Dare telling you not to shoot it, you are the one that makes her not shoot the engineer, and, basically telling him 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]] with 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.]]
* BoomHeadshot: There are two Achievements for shooting enemies in the head. One is called "Boom, Headshot".
* CanonImmigrant: The game introduces a new Covenant unit: the 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 now. The Engineers have always had a presence in the Halo ExtendedUniverse, but it took design 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: 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.
* DisproportionateRetribution: 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.
* {{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...
* FakeStatic: 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 saxaphone solos]] in the music.
* FireForgedFriends: The entire ODST squad counts, but specifically the Rookie, Buck, and Dare.
* FollowTheLeader: The "Firefight" mode is the Halo version of the ''VideoGame/GearsOfWar'' "Horde" mode, which many other shooter games have adopted.
* 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 2:20 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?
** Buck is described in-game as being so good that he could be a Spartan. Come ''VideoGame/Halo5Guardians''...
* GentleGiant / BewareTheNiceOnes: Jonas. 6'10, 500 pounds, and is very soft-spoken, 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
* 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. He refuses to leave New Mombasa because he would take up too much room, and flatly insists his life isn't worth 5 others.
* HubLevel: After the first level the Rookie runs around "Mombasa Streets", 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. The hub also has enemies and terminals which give backstory to New Mombassa.
* InkSuitActor: Both Creator/NathanFillion and Tricia Helfer'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, [[TheLastDJ his skills are too valuable to simply let go]].
* LateToTheTragedy: The Rookie spends most of the game playing catch-up.
* 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]] [[RedShirtArmy Red Shirts]] deployed for a single mission that spans less than half a day of narrative time, in contrast to the series usual stories of a SuperSoldier who alter the course of the war, fights an EldritchAbomination, and prevents genocide on a galactic scale.
* {{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.
* 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, he is the Rookie's guide for most of the game, as well as telling you 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.]]
** Them 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 here.
* 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]]."
** HilariousInHindsight: [[spoiler:Buck and the rest of his squad (save Dutch and the Rookie) eventually become Spartan-[=IV=]s after the events of Halo 4.]]
* ShootTheMedicFirst: Engineers give its 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'':
*** 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; He is your only companion (as The Rookie) for most of the game. He guides you and tells you the story of what happened when you were asleep in your pod, this is very similar to other character named Virgil from ''The Divine Comedy''.
*** 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]].
* 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 openly angry at her and she eventually starts letting her affection show through.
* 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.
* ThreeVolleyFlinch: In ''[[https://www.youtube.com/watch?v=w5Dc2At5_AE The Life]]'', one of the ads for this game, 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: [[spoiler:The NMPD officer in Data Hive, who is your ally for much of the level.]]
** The [[EliteMooks Drone Leaders]], which are golden and have energy shields.
''Bam, said the lady.''