-->'''Master Chief:''' "Sir, permission to leave the station."\\
'''Admiral Hood:''' "For what purpose, Master Chief?"\\
'''Master Chief:''' "[[RidingTheBomb To give the Covenant back their bomb]]."

The second game in the ''{{Franchise/Halo}}'' series, released in 2004; it is the highest-selling game for the original [=XBox=].

Following the events of the first game, Master Chief arrives back at Earth, praised as a hero. In the midst of celebration, a Covenant attack begins on Earth, and Master Chief races to stop them. He learns that the Covenant are looking for something on Earth, and his quest takes him to a new Halo ring, where he explores more of the mystery behind The Flood.

The major change from the first ''Halo'' game is that the campaign is told from two different angles: that of Master Chief, and that of a member of the Covenant, a soldier in the EliteMook race from the first game (the actual character is introduced in this game). He is known only as [[KnownOnlyByTheirNickname the Arbiter]], and he was originally the leader of the Covenant forces that encountered Master Chief on the first Halo ring. Disgraced by the Covenant leaders due to his failure to stop the ring's destruction, the Arbiter is given a suicide mission that may potentially help him reclaim some of his lost honor. As the Arbiter learns more about the origin of the Halo rings and fate of the Forerunners, he eventually comes to doubt the Covenant cause...

On the gameplay side, ''Halo 2'' introduced DualWielding with a class of weapons you can pair off with any other type in the same class (this is portrayed as something only Master Chief, Covenant Elites, and Covenant Brutes can do). It also featured vehicle hijacking - assuming you could get close enough to the vehicle without being gunned down or run over. ''Halo 2'' solidified the presence of online console gaming thanks to the original ''[=XBox=] Live'' service; thanks to ''Halo 2's'' success, practically any game of nearly any genre will have at least some debate from the developers on whether or not it should feature an online component.

After several rumors concerning an UpdatedRerelease to mark its [[MilestoneCelebration ten year anniversary]], ''Halo 2: Anniversary'' was announced to be released on November 11, 2014, as part of the compilation ''Halo: The Master Chief Collection''. It will come with updated graphics and other bonus content, but unlike ''Halo: Combat Evolved Anniversary'', its multiplayer will be the same as the original.
!!Halo 2 contains examples of:

* AlienSky:
** Once Master Chief gets to Delta Halo, If you have a good view of the sky, things often look... alien.
** Your first mission as the Arbiter puts you on a station at the edge of a gas giant's atmosphere. It's all angry swirling clouds.
* ArtEvolution: The graphics are significantly improved from the original, despite being released for the same system.
* AwesomeButImpractical: If you want to complete the level Metropolis as fast as possible, you'll have a much easier time if you take the Warthog instead of the tank the devs thought you would.
* BadassBoast:
--> '''Lord Hood:''' Master Chief, you mind explaining what you're doing on that ship?\\
'''Master Chief:''' Sir, [[{{Halo 3}} finishing this fight.]]
* BigBulkyBomb: The Covenant boarding parties bring one onto Cairo station, and a [[SuicideMission suicide-squad]] of [[EliteMooks Elite Zealots]] guard it while waiting for it to detonate. The thing is easily bigger than any one of them or the Master Chief, and is covered in spikes.
* BoringButPractical: The Battle Rifle, a normal, burst fire human rifle with a 2x scope. It kills Grunts and Jackals with one headshot burst, even on Legendary, and when used in combination with the plasma pistol is also capable of absolutely ''destroying'' Elites. It can also allow you to out snipe Jackals and the ammo for it is usually plentiful.
* CliffHanger: The story ends with one of the most infamous cliffhangers in all of videogaming, being a very obvious SequelHook rather than actual completion of the main threats a'la the first game.
* DeadpanSnarker: Cortana, so, so much.
-->'''Cortana:''' Ask yourself this question: "Is what I'm doing right now helping Cortana keep this station from exploding into tiny, tiny bits?"
* DeathSeeker: The Arbiter. Pretty much comes with the job description.
* {{Determinator}}: Meta example. The only thing that ended ''Halo 2'''s online gaming scene was the original Xbox Live servers getting ''shut down''. The game was launched on Nov 9th, 2004, and the servers officially shut down on Apr 15, 2010. Officially, that is; several players hung on until getting booted on May 11th.
* DualWielding: The first game to have a set of weapons that you can randomly pair with other designated one-handed weapons.
* EarlyBirdCameo: An example map in the PC port includes a version of the SMG with a slightly-smaller magazine and a suppressor. This silenced SMG returned in ''Halo3ODST'' as the primary weapon of the titular ODST squad.
* EnemyCivilWar: Following [[spoiler: the assassination of the Prophet of Regret]], the Elites are stripped of their traditional role as honor guards to the Prophets, which is given to the Brutes. The Elites do not take kindly to this, and end up seceding from the Covenant, along with several individuals of other species.
* EnemyMine: The Gravemind recruits Master Chief and the Arbiter, making it a three way enemy mine.
** Also, [[spoiler:Sergeant Johnson, Miranda Keyes allying with the Elites (especially the Arbiter) and two Hunters.]]
* FireKeepsItDead: When the Flood turn up one of the Arbiter's fellow Sangheili laments that they didn't bring anything to burn the bodies with.
* HeyItsThatVoice: Orlando Jones("That thing is really starting to ''piss me off!''), Michelle Rodriguez("It blew right through us! Rockets, .50 cal, they didn't do a thing!"), David Cross and John Kassir (aka [[TalesFromTheCrypt The Crypt Keeper]]) were varous Marines.
** {{Julie Benz}} voices Miranda Keyes.
** [[That70sShow Donna Pinciotti]] gives you a shotgun.
** [[Creator/RonPerlman Hellboy]] is your commanding officer.
* HoistByHisOwnPetard: After the Chief deactivates the antimatter bomb on board ''Cairo Station'', he proceeds to take it down to a hangar, open the doors, and use the decompression to hurl the bomb toward a Covenant carrier. [[SerialEscalation But wait, that's not all!]] He ''grabs hold of the bomb'' so that he can activate it right inside the carrier's reactor, before jumping off again and landing on a passing frigate.
-->'''Master Chief''': Sir, permission to leave the station?
-->'''Lord Hood''': For what purpose, Master Chief?
-->'''Master Chief''': [[BadassBoast To give the Covenant back their bomb]].
-->'''Lord Hood''': [[{{Beat}} ...]] permission granted.
* JustifiedTutorial: Master Chief gets an upgraded armor system (Mjolnir Mark VI) that gives an InUniverse explanation for some of the gameplay changes (no more need for health packs, supposedly there is an internal "bio foam" system). As well, the technicians have him look around to get adjusted to the new armor.
* MadeOfExplodium: Covenant vehicles in this game, more so than the other games. Do enough damage and they violently explode. Twice.
* NeoAfrica: New Mombasa, Kenya is a high tech city and spaceport. At least, when the game begins.
* NeverTrustATrailer: The trailers, promotional materials and even the blurb on the game's box all gave the impression that the Chief would spend all or most of the game helping humanity repel the Covenant invasion on Earth.
* OldShame: Some of the devs [[ don't like]] how the single player campaign turned out, if the term "disastrous flaming turd of failure" is an expression of regret.
** Which makes the fact that it's the only Halo game ''not'' on XboxLive not that hard to understand.
* OptionalStealth: The Arbiter's InvisibilityCloak lasts for only about five seconds anyway, so ignoring it is perfectly viable option if you don't like having to wear down all your enemies versus getting one free assassination. A bonus item lets Master Chief have invisibility too, but it lasts for the same amount of time and the second disadvantage of no visible timer.
* {{Retcon}}: Master Chief (with Cortana) was the only human to survive the destruction of the first Halo. The Legendary ending of the first game even gave a (humorous non-canon) scene depicting Johnson's last moments before the Autumn exploded. This game just has him show up in the medal ceremony with no explanation given. ''Literature/HaloFirstStrike'' had to explain how he survived.
** [[LampshadeHanging Lampshaded]] shortly after Johnson first reappears:
-->'''Mst. Sgt. Gunns:''' So, Johnson, when you gonna tell me how you made it back home in one piece?\\
'''Sgt. Johnson:''' Sorry Gunns, it's classified.\\
'''Mst. Sgt. Gunns:''' ''[[AssPull My ass!]]'' Well you can forget about those adjustments to your A2 scope, and...''(continues shouting as Johnson and Chief move out of earshot)''
* RightHandVersusLeftHand: The Covenant infighting between the Brutes and the Elites leads to a schism in the Covenant and basically the only hope for Humanity's survival.
* SequelHook: Also one of the most infamous ones in video game history.
* TheMissingno: The Gravemind mission has the "Honor Guard Councillor", a Zealot (gold) elite that was accidentally programmed to have a "dogmatic" voice/personality; since the level has no permutation data for dogmatic Elites, it defaults to Honor Guard armor and Ultra palette, with randomly chosen head types(most frequently the Councillor, hence the nickname).
* ThisCannotBe: In the final mission, when the presumed dead Arbiter returns to confront Tartarus.
-->'''Tartarus:''' ''(gasps and jerks his neck up in surprise)'' Impossible!
* TookALevelInBadass: The generic [[RedShirtArmy UNSC Marines]] got way more competent since Halo 2. They're more accurate, they have twice as much health, and they can drive vehicles. They're actually pretty helpful when they appear as long as you throw any submachine guns and shotguns you find in the trash and replace them with Battle Rifles and Sniper Rifles. Give one a rocket launcher and the marine's good aim and unlimited ammo will usually let him rack up almost as many kills as you.
* TrailersAlwaysLie: The E3 demo (and the advertising, ''and'' the boxart) gave the impression that the game would be set on Earth's surface. The final game had a grand total of two levels set there.
** In a more straight version of the trope, the "Give them back their bomb" sequence in the trailer has Earth in '''''much''''' more trouble than in the actual game, in which the Covenant barely stick around for. Earth's on fire? Not really. [[spoiler:Save that for the next game and ODST.]]
* TranslatorMicrobes: Cortana, being an advanced A.I., can understand the Prophets language. ''And'' she can translate it for others to hear.
-->'''Prophet of Regret message:''' ''*speaking alien language*''
-->'''Cortana:''' The Prophet of Regret is planning to [[OhCrap activate Halo!]]
-->'''Master Chief:''' Are you sure?
-->'''Cortana:''' ''*snaps fingers*''
-->'''Prophet of Regret:''' ''*English*'' I shall light this holy ring, release its cleansing flame, and burn a path into the divine beyond!
-->'''Cortana:''' ''*snaps fingers*'' Pretty much.
* TwoLinesNoWaiting: The game is divided between master Chief and the Arbiter. Gameplay wise they play almost the same, except one has [[InvisibilityCloak Active Camouflage]] and the other has a flashlight.
* TwoPartTrilogy
* WhamEpisode: The cutscenes between "Quarantine Zone" and "Gravemind"; [[spoiler: the Flood have a leader and the EnemyCivilWar begins.]]
** WhamLine: From the same cutscene.
--->'''Tartarus:''' A bloody fate awaits you and the rest of your incompetent race. And I Tartarus, chieftain of the Brutes, will send you to it.
--->'''Arbiter:''' When the Prophets learn of this, they will take your head.
--->'''Tartarus:''' When they learn? [[spoiler:Fool, they ordered me to do it.]]
** "The Arbiter" was one originally, before everyone knew that half the game was spent playing as the Arbiter.
* WhatCouldHaveBeen: Nearly a third of it was cut out due to wasting time on the engine. For one, it was supposed to end the series. For two, ''[[SoCoolItsAwesome Forerunner Tank.]]''
** ''Forerunner Tank'' was a level that was cut from the game very early in development. That said, it gained the above trope because of what the developers said about it: "Awesomeness would ensue."
** Not to mention the demo of the game. It appears that everything they had in the demo that ''wasn't'' used in Halo 2, was used to make an entirely new game; Halo3ODST.
* YouHaveOutlivedYourUsefulness: [[spoiler: Tartarus is ordered by the Prophets to kill the Arbiter after Delta Halo's Index is secured.]]
* YouHaveFailedMe : The Elites as a whole suffer this [[spoiler: after Chief kills the Prophet of Regret]], as the surviving Hierarchs attempt to replace them with the Brutes. [[EnemyCivilWar The Elites don't take it very well]].