Editing UNSC Marine Corps/Gameplay

{{Status|Gameplay}}
[[File:Marine Evolution.jpg|thumb|250px|From left to right: Marines in ''[[Halo: Combat Evolved]]'', ''[[Halo 2]]'', ''[[Halo 3]]''/''[[Halo 3: ODST]]'', and ''[[Halo: Reach]]''.]]
The '''[[UNSC Marine Corps]]''' and its personnel serve as the primary ally throughout most of the [[:Category:Games|''Halo'' games]]. They also appear in ''[[Halo: Reach]]'', but the [[UNSC Army]] is the [[UNSC Army/Gameplay|main NPC ally]]. ''[[Halo 5: Guardians]]'' is the first game in the main series not to feature them at all in the campaign.

==''Halo: Combat Evolved''==
[[File:Marines on the Battlefield.jpg|thumb|Several Marines fighting along side the [[John-117|Master Chief]] to take the [[Control Room]] of [[Installation 04]].]]
The Marines serve as the main allies in the first six levels of ''Halo: Combat Evolved''. Aside from assisting the player in combat, Marines can also be used to provide extra firepower on certain vehicles such as [[Warthog]]s and [[Scorpion Tank]]s. In-game, they are unable to operate the vehicles themselves, but they are capable of piloting {{Pattern|Karo'etba|Ghost}}, albeit clumsily.

Marines wield [[MA5B assault rifle]]s as their primary weapon in combat. However, they can sometimes be seen wielding other weapons such as the [[Sniper Rifle]] (as seen in the level 'Assault on the Control Room' and 'Halo'), the [[Shotgun]] (as seen in the level '343 Guilty Spark'), and even Covenant [[Needler]] or {{Pattern|Okarda'phaa|plasma rifle}} (as seen in the levels 'Assault on the Control Room' and 'Truth and Reconciliation') to give them an advantage against shielded enemies. Marines also often utilize [[Fragmentation Grenade]]s (mainly when Ghosts get near or on a group of elites) in combat. They are relatively accurate with their weapons, with a hit percentage upwards of 50%. 

The Marines' AI is built very simplistically. They will occasionally strafe to avoid fire and will react to the environment within their vicinity by maneuvering around obstacles or rolling out of the way if there is an upcoming vehicle or grenade. However, they will usually not seek cover and will occasionally be susceptible to friendly fire as they will stand in either the player's or other Marines' line of fire. They are also vulnerable from taking heavy fire as it will render them unable to shoot or move, making them nearly useless on higher difficulties. They also cannot pick up different weapons, [[Health Pack]]s, or additional ammunition. 

Performance-wise, Marines can be very effective in helping the player dispatch a horde of enemies, depending on the chosen difficulty. They are able to quickly defeat [[Unggoy/Gameplay|Grunts]], [[Kig-Yar/Gameplay|Jackals]], and sometimes a [[Sangheili Minor|Minor Elite]] in groups. However, they will easily be overwhelmed if facing against [[Mgalekgolo/Gameplay|Hunters]] or higher-ranking Elites. Marines are also very ineffective when facing against the Flood, often take heavy if not total casualties. A single stray [[Pod infector]] is enough to kill a Marine; if the creature attaches itself to the soldier, it cannot be shaken off and will instantly kill them. Incidentally, a stray melee attack from the player will instantly kill them, regardless of difficulty.

Marines are conscious of fratricide. After you have killed two humans of any type, the rest of the Marines in the campaign level will attack the player. If one kills [[Captain Keyes]], or any other members of the bridge crew, in the campaign level ''[[Pillar of Autumn (Level)|The Pillar of Autumn]]'', [[Cortana]] will lock the doors and summon a squad of invincible Marines to kill you.

They also go "berserk" when they have taken too much damage. When down to one last bit of health, they will scream something (such as: "I'll take you all on!" or "Who wants a piece of me?!") then rush in a straight line toward the nearest enemy and fire in extended bursts (5-7 round burst as compared to 2-3 round bursts). This is usually the last thing they ever do, as they are badly wounded by this time and the lack of any melee attack (or the use of full auto with an assault rifle) and running-in tendency makes them very vulnerable in the close-range combat, and often end up getting killed after going "berserk". If a "berserk" Marine survives a fight, he will calm down and simply return to normal.

==''Halo 2''==
[[File:Trouble.jpg|thumb|A Marine [[ODST]] preparing to engage an enraged [[Brute]].]]
In ''[[Halo 2]]'', the Marines have undergone major improvements from ''Halo: Combat Evolved''. 

The most drastic change is their higher health pool. They can now outlast against multiple hordes of enemies than they did in Halo: CE, and even withstand from a single melee attack from the player, albeit if they're not heavily wounded. However, like the player, they can still be killed by being melee'd in the back, and will quickly be killed if facing against [[Type-1 energy sword|Type-1 Energy Sword]]-wielding Elites. While the health bar for the Marines are no longer visible while riding on vehicles, a visual cue is implemented to detect their condition; if a Marine is wearing a helmet, it can be shot off to expose their head.

Marines can now perform stealth kills by meleeing sleeping Grunts and will even attempt assassination kills if they catch the enemy unaware. However, they lack the brute strength to kill Elites in this manner. Also, they are now able to take cover behind walls, corners, and obstacles with their backs up against them when under fire, something the players themselves are unable to do.

The player is now given the option to swap weapons with Marines. This is done to maximize their effectiveness against multiple types of enemies, (i.e. plasma weapons against Elites or the [[M19 Rocket Launcher|Rocket Launcher]] against vehicles). However, they will not accept an empty weapon, and cannot wield [[Jovokada Workshop brute shot| Brute Shots]] and [[Type-1 energy sword|Energy Swords]]. Marines also lack the ability to dual wield (although dual weapons can sometimes be found next to their corpses in certain levels).

Marines are more adept with vehicles. They can now drive [[Warthog]], the {{Pattern|Karo'etba|Ghost}}, the [[Zurdo-pattern Wraith|Wraith]], and the [[Scorpion Tank|Scorpion]]. They can also flip lopsided vehicles like the Ghost. 

Although their friendly fire incidents have decreased, contrary to popular belief, Marines do use fragmentation grenades in combat (more likely when betrayed), albeit quite rarely, and are unaware of splash damage from heavy weapons, sometimes firing a rocket into a nearby wall and killing themselves. 

The Marines are far more interactive, sometimes speaking to each other while in combat, taunting their enemies and wield a greater variety of weapons. As in ''[[Halo: Combat Evolved]]'', the Marines are aware of backstabbing, and will attempt to kill you after you kill a few of their comrades. The number of Marines that can be killed before the others turn against you oddly seems to vary depending on the weapon used and the way they are shot. 
[[File:H2AMarines.jpg|thumb|300px|A squad of marines suiting up during the [[Battle of Earth]].]]

===Changes from ''Halo: CE'' to ''Halo 2''===
*Players can now swap weapons with their marine allies.
*Marines now have the ability to [[melee]].
*Marines can now drive vehicles smoothly.
*Marine armor is green color based rather than grey.
*Marines' helmets can pop off if shot with a direct hit.
*Marines no longer have the green screen over their eye.
*Marines have significantly more dialogue lines.
*Marines respond to and react to one another's speech in non-scripted ways; if one marine cracks a joke another one will laugh.
*Marines seem to have about 75% more health.
*Marines are able to flip Ghosts.
*Marines now have less chance to have friendly fire with other Marines when they are in the line of fire.
*Marine's Health bar can no longer be seen when mounted on a vehicle.
*Marines are no longer stunned every time they are hit.

==''Halo 3''==
[[File:H3 Marines firing weapons.jpg|thumb|4 UNSC Marines on the [[Crow's Nest (Base)|Crow's Nest]], concentrating their fire on killing a swarm of [[Yanme'e|Drones]].]]
In ''[[Halo 3]]'' they can, once again, utilize the Grunts' weakness for naps by using stealth and hitting them, usually with a kick, but they can also hit something with their rifle. However, as they lack the physical strength compared to many races of the Covenant, UNSC Marines will usually lose in melee combat with vicious ballistic creatures such as the [[Brute]], meaning they often have to rely on their group-tactics to defeat one. They seek cover much more often and even put their back up to the wall. They will throw grenades much more often, and with great accuracy, especially in higher difficulty [[levels]]. They will sometimes also display group tactics never seen in previous games, like huddling into a tight group and combining assault rifle fire while combating Drones. Even though the Marines are smarter in Halo 3 they occasionally will make mistakes, such as running off a cliff while driving a vehicle. Marines/ODSTs seem to be able to react with the environment around them. For example, if a Ghost is about to explode, they will stand back or walk around it and continue after it explodes. Despite this, their AI was considered poor compared to the enemy AI (such as the Covenant and Flood). 

The player can still exchange weapons and ammo with them, though they won't accept Brute Shots, Gravity Hammers, Sentinel beams or Energy Swords (Except Johnson on the level [[Halo (Halo 3 level)|Halo]]). Marines in Halo 3 have infinite ammo for their weapons, which can be exploited by giving Marines heavy weapons.

After killing two of them, any that are left in the area will come to kill you. After a while (even if you are constantly killing them) they will see you as a friend again. Interestingly, their accuracy becomes 100% if betrayed, and if there are two or more remaining Marines they can end the Chief's life in a matter of seconds.

Their audio clips have also been vastly expanded, and profanity is used to indicate wounded status if the IWHBYD skull is activated. Their appearance has also changed, and they have a lot more face models.

Marines in ''Halo 3'' are much more reliable when facing against the Flood than in ''Halo: Combat Evolved''. The option to kick can allow them to repel Pod infectors, and there is a longer lag duration the Pod infectors will undergo, in order to successfully attach themselves onto the Marines. If a Pod infector attaches itself on a Marine, they will grapple for a second or so, to give the player a chance to shoot it off. Otherwise, the Pod infector will mutate the Marine into a Combat Form. It is possible to "short circuit" the mutation by firing on the new Flood host, thus preventing Marine to not fully mutate. Despite these improvements, Marines are still vulnerable to infection, especially in comparison to the Sangheili allies. If not given Shotguns or Assault Rifles, they will suffer heavy casualties. So it is up to the player to provide them with such weapons to ensure their survival utmost.

Marines are seen in larger groups in Halo 3. In previous games they were usually seen in groups of 4-6, or one squad. Now several squads can be seen at a time, and all are able to assist you.

Marines have also gained the ability to flip vehicles, which compensates well for their somewhat poor driving. They can flip the [[M274 Mongoose|Mongoose]] or [[Karo'etba-pattern Ghost|Ghost]] by themselves, and can flip the [[Warthog]] when in groups of at least three, and strangely, they can flip the 66-ton [[M808B Main Battle Tank|Scorpion]] in groups of only five.

Marines' accuracy is also much greater and it seems they now have the ability to lead their targets, allowing them to take down Brutes driving [[Barukaza Workshop Chopper|Chopper]]s or Grunts driving [[Karo'etba-pattern Ghost|Ghost]]s with greater ease. This can be seen if the player drives a [[Mongoose]] with a Marine passenger using a Rocket Launcher on [[The Ark (level)|The Ark]].

===Changes from ''Halo 2'' to ''Halo 3''===
*Marines now lead their targets. (This works especially when using the Rocket Launcher or Fuel Rod Gun)
*Accuracy with heavy weaponry increased considerably.
*Marines can now climb up on an object if it is low enough.
*Marine's accuracy when firing weapons from vehicles increased.

==''Halo 3: ODST''==
For the most part, Marine allies in ''[[Halo 3: ODST]]'' are near-identical to their counterparts in ''Halo 3'', though there have been a number of improvements made by Bungie. For one thing, driving and movement AI is far superior, including their pathfinding ability. Accuracy has also been increased, whether on foot with handheld weapons, or using turrets. "Gunners" using the machinegun turret of an M808B Scorpion tank are also improved, with better targeting than their past incarnations.

==''Halo Wars''==
[[File:Burningcritters.jpg|thumb|200px|Marines, accompanied by [[Flamethrowers|Flamethrower squads]], deploy into combat.]]
In ''[[Halo Wars]]'', Marines are built in "squads" of four (or five when you upgraded them with New Blood).

Their starting special ability is a grenade attack which can be upgraded to RPGs. They have up to three upgrades:<ref>[http://www.xbox.com/NR/rdonlyres/31804095-7B32-4CE2-A17E-3CB54A3692EF/0/HaloWars_MNL_EN.PDF Planetary Operations Manual]</ref> 
#"''New Blood''": Adds one extra marine to each group, increasing the damage they deal over the same length of time and slightly increasing maximum health.
#"''RPG''": Upgrades the [[Frag Grenade|Grenade Toss]] active ability to the [[M19 SSM Rocket Launcher|RPG]] active ability, which has a longer range and deals more damage.
#"''Medic''": Adds a fighting [[medic]] to each group, which allows injured Marine units to heal while not taking damage.

In addition, if the player selected [[James Gregory Cutter|Captain Cutter]] as their Hero, the [[Marine]]s can be upgraded to [[Orbital Drop Shock Troopers|ODST]]s, which have more maximum health, deal more damage, and have higher defense. In addition, ODSTs can be deployed anywhere on the battlefield with the "ODST Drop" Hero Ability.<ref>''Gamepro'' #238, pp50</ref>

Marines armed with the [[M6634 flamethrower]] are built as [[Hellbringers|separate units]] called "Flamethrowers". Flamethrowers received upgrades such as [[Flashbang grenade]], which stuns enemy infantry temporarily, and Napalm Adherent, which causes enemies attacked by Flamethrowers to burn for several seconds after the initial attack, causing damage over time.<ref>''Gamepro'' #238, pp50</ref> Like Marines, Flamethrowers can be created at the [[UNSC Barracks]] or trained via a deployed UNSC [[Elephant]], though like the ODST upgrade, the latter is only possible if Captain Cutter is the selected Hero.

==''Halo 4''==
The marines' intelligence appears to have degraded significantly with several notable flaws. Marines appear to fire at recently deceased enemies for rather prolonged periods of time, even in the middle of combat, which can get them killed.

Marines tend to have an extremely poor performance in vehicular combat. While driving, marines will often drive rather slowly and not take any form of evasive maneuvers, which can easily spell doom to players on higher difficulties. While their performance on a turret is much better than behind the wheel, they suffer the same flaw of shooting dead enemies while ignoring live ones. It also does not help that marines have a maximum range that is smaller than that of enemy vehicles, meaning that they ''will not'' fire upon an attacking ghost until you're practically right next to it.

Finally, while marines are generally accurate and effective with heavy weaponry, they have been known to accidentally kill themselves or their allies, the player included, in close-quarters scenarios.

==''Halo 5: Guardians''==
Marines are not present in Campaign mode, though Liang-Dortmund private security forces take essentially the same role in missions set on Meridian. They will generally follow the player. They are equipped with Sniper Rifles, M20 SMGs, MA5D assault rifles, BR85 battle rifles, and M6H2 magnums. They have reasonable accuracy. If shot or hit with a melee attack from the player, they will yell something at you. No matter how many are betrayed, the survivors will not attack you.

For the first time in the series' multiplayer (excluding the ''Halo Wars'' strategy games), Marines make an appearance in multiplayer, serving as NPCs in the [[Warzone]] gamemode. Here, they defend captured bases. They spawn immediately after capturing a base and will not move outside of it. Unlike in previous appearances, the armour of the Marines is not camouflage, but instead colored in the color of the team they spawn for (Red or Blue). When approaching a friendly base, the Marines will wave to the player and speak to them.

They will not trade weapons and do not pick up weapons, nor will they enter vehicles. They are equipped with an MA5D Assault Rifle or a BR85 and frag grenades.

In terms of quality, the Marines can hit very accurately and constantly fire when enemies are within range. Three Marines can easily over power a single SPARTAN. However, they can be easily killed by headshots or silenced weapons. Like every other Warzone AI enemy, Marines have their health increased a bit.

==''Halo Wars 2''==
Marines come out of Firebases with a squad of four by default and cannot throw grenades. The number of Marines per squad can be increased to five if player researches the Combat Technician upgrade. They have two upgrades for combat and if paired with a [[Mastodon]], they can be very lethal all-rounder units.

#"''Grenade Throw''": Enables Marines to throw grenades.
#"''Combat Technician''": Adds a Combat Technician with a rocket launcher to a Marine squad, who is able to heal allied vehicle units, mechanical units, and structures.

===Changes from ''Halo Wars'' to ''Halo Wars 2''===
*Standard Marine units are no longer equipped with Grenade Throw, which must be researched.
*Two researches are needed to fully upgrade Marines instead of three.
*Marines are now affected by the Infantry upgrade from Barracks and Logistics Upgrade from the Armory.
*Marine production moved from Barracks to Firebase.
*Marines will be transported via Pelican to the Firebase or a Minibase when the player trains an Infantry unit.
*Upon researching Combat Technician, marines can only heal non-infantry, with healing infantry is now relegated to [[EV-44 Nightingale]].
**Marines also no longer self-healing when out of combat.
*Marines no longer upgraded to ODST, as it becomes exclusive to Captain Cutter through Leader Power ODST Drop.

==Trivia==
*In the in-game game mechanics, Marines actually possess regenerating armor that functions similar to the regenerating energy shields possessed by the Master Chief and enemy Elites. However, unlike energy shielding, this armor does not have special damage values (i.e. it does not take reduced damage from bullets or increased damage from plasma). In ''[[Halo: Combat Evolved]]'', a Marine's armor is about 50% as strong as a [[Minor Elite]]'s shields. In ''[[Halo 2]]'', the armor appears to be on par with a Minor Elite's shielding, allowing a Marine to take roughly the same amount of damage as a Minor Elite.
*In ''[[Halo: Combat Evolved]]'', shooting a dead Marine's armor with a ballistic firearm would eventually send a ricochet at your shields. Meleeing them would result in a loud "''clack''" However, in ''[[Halo 2]]'' and ''3'', the bullets do not ricochet, but penetrate the dead bodies and result in a large amount of blood.
*In ''[[Halo 2]]'', Marines receive a significant upgrade in both A.I. and durability. A ''Halo 2'' Marine can survive as much damage as a fully shielded blue Minor Elite, and use intelligent combat tactics (such as using cover and firing from behind cover, combining fire-power and flanking manouvers) that can allow small groups of 2 to 5 Marines to hold their own against large squads of the "inferior" Covenant enemies ie Grunts and Jackals. This is especially noticeable on Legendary difficulty due to the way their AI is scaled, which increases their accuracy by the same degree as enemy units and often leads to Marines scoring multiple headshots in quick succession.
*In ''[[Halo 3]]'', Marines are likewise highly resilient, with a single Marine having roughly the same level of durability as a Brute Minor (on Heroic difficulty a Marine takes about 24 assault rifle shots to kill, whereas a Brute Minor takes 7 shots to drop their shield and an additional 17 shots to kill).
*In ''[[Halo 3]]'', Marines generally tend to care greatly about the welfare of the [[John-117|Master Chief]], and become scared and upset if he dies. However, when playing Co-op with the Arbiter, if the Arbiter dies, the Marines don't seem to care at all and act as if it's unfortunate, but still unimportant.
*In ''[[Halo 2]]'', sometimes if you kill ally Marines until they betray you, they will yell phrases like, "''I have been waiting for this for a long time!''", "''You won't get away with that!''", or "''Kill the traitor!''". In ''[[Halo: Combat Evolved]]'', they will yell out things like "''Let's end this!''", or "''I've had enough of this crap!''"
* In ''[[Halo 3]]'', when Marines approach the bodies of dead Marines, they will crouch beside them, place their hand on the body, and usually utter something like, "''I'll make sure your letter gets to your parents,''" or "'''Better you than me.''" If there are groups of Marines dead, other Marines will, upon discovering the scene, utter things like, "''What happened here?''" or "''Poor buggers, never stood a chance.''" During [[Crow's Nest (Level)|Crow's Nest]], in the Barracks portion of the level, this is a common sight. Marines can also be quite callous when around dead Marines, particularly with the [[IWHBYD Skull]] activated, sometimes making statements like, "''He had a watch on him,''" or "''I never liked him anyway,''" or "''Where is that watch?...''"
*In any of the ''[[Halo]]'' trilogy games, Marines will kill an enemy, and then, seemingly in celebration, shoot the dead body for a few seconds, while yelling things like, "''I saw it move!''" or "''Get up so I can kill you again!''".
*In ''Halo Wars'', Marines are a unit. Oddly, although your max population is 40, you can train up to 41 Marines. The same is true for grunt squads.
*In ''Halo: Combat Evolved'', Marines will sometimes pilot Ghosts. While they can be useful in combat, Marines are terrible at steering the Ghost and they will often run over the player if you are not careful.

==See also==
===Internal articles===
*[[United Nations Space Command]]
*[[UNSC Marine Corps]]

==Sources==
{{Ref/Sources}}

[[Category:Gameplay guides]]