Editing M68 Gauss cannon

{{Status|Canon}}
{{Center|''This article is about the model introduced in Halo 2. For the model introduced in Halo 5: Guardians, see [[M70 Gauss cannon]].''}}
{{Weapon infobox
|image= [[File:Gauss turret.png|300px]]
|manufacturer=[[Misriah Armory]]
|series=M68
|type=[[Magnetic Accelerator Cannon]]
|cost=
|variant=
|service=[[Human-Covenant War]] <br> [[Post-Covenant War conflicts]]
|affiliation=[[United Nations Space Command]]
|weight={{Convert|243|lb|kg}}<ref name="ENC">'''[[Halo Encyclopedia (2009 edition)]]''', ''UNSC Weapons'', ''page 321'' (2011 edition)</ref>
|length={{Convert|119.6|in|cm}}<ref name="H4VG">'''Halo 4: The Essential Visual Guide''', ''page 80''</ref>
|width={{Convert|55.6|in|cm}}{{Ref/Reuse|H4VG}}
|height={{Convert|85.8|in|cm}}{{Ref/Reuse|H4VG}}
|ammotype=25x130mm <span class="explain" title="armor-piercing, limited penetration/frangible">APLP/F</span>{{Ref/Reuse|ENC}}<br/>
25x130mm M485 HV/FTHPP{{Ref/Reuse|vis}}<br/>
[[Anvil round]] {{C|When specially-modified}}<ref name="PL">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]] - Forge's Warthog''</ref>
|capacity=
|feed=750 rounds{{Ref/Reuse|ENC}}
|operation=[[Wikipedia:Coilgun|Asynchronous linear-induction motor]]
|rate=Semi-automatic 
|velocity=
|optics=
|range={{Convert|8|km|mi}}{{Ref/Reuse|ENC}}
}}

The '''M68 Asynchronous Linear-Induction Motor''', more commonly known as the '''M68 Gauss Cannon''' (named after nineteenth century physicist [[Wikipedia: Carl Friedrich Gauss|Carl F. Gauss]]),<ref name="vis">'''[[Halo: The Essential Visual Guide]]''', ''page 78''</ref> is a [[weapon]] that fires hyper-velocity, high-density projectiles similar to those of a [[Magnetic Accelerator Cannon]], except on a much smaller scale.<ref>'''[[Halo: Reach]]''', ''Game Stats''</ref><ref name="PH">'''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''', "[[Palace Hotel]]", ''page 362''</ref>{{Ref/Note|1=''"While the Warthog gauss rifle is modeled as a magnetic acceleration cannon, the sound and effects are actually those of a railgun, which operates on a different principle. However, the sound and effects were so cool that we couldn't not use them."''<br />— ferrex providing [http://www.bungie.net/Forums/posts.aspx?postID=27004812 additional information] about the M68.}} Also known among the troops as the "68," "Rail Gun," "Tent Pole," and the "Gas Gun,"{{Ref/Reuse|ENC}} it can be mounted on a stationary stand, or on the rear of the [[M12G1 Warthog LAAV]].

==Design details==
===Operation===
The M68 ALIM uses an [[Wikipedia:Linear motor|asynchronous linear-induction motor]] to produce a bipolar magnetic field capable of launching a 25x130mm projectile at an incredible speed of just under Mach 40, or approximately 13.7&nbsp;km per second.{{Ref/Reuse|PH}}{{Ref/Note|The speed of the Gauss Cannon's projectile in-game is much slower than its canonical speed of Mach 40. This is probably because of design and engine limits as well as balancing issue. The projectile moves more quickly in ''Halo 3'' than in ''Halo 2''.}} The great velocity of the projectile is the key to the stopping power and performance of the Gauss cannon, giving it exceptional armor penetration at impressive ranges.

When modified, Gauss cannons are capable of firing the [[Anvil round]], a special kind of ammunition capable of causing an [[Electromagnetic pulse|EMP]] in the target area and doing more damage than standard munitions.{{Ref/Reuse|PL}}<ref>'''[[Halo Wars 2]]'''</ref>

===Role===
The M68 ALIM is primarily used in an anti-vehicle capacity by UNSCDF ground forces, though it can be used to devastating effect against infantry. It is often seen mounted on the Warthog in the same manner as the M41 LAAG, and while it does not possess the LAAG's extreme rate of fire, it displays near-pinpoint accuracy and overwhelming firepower, usually killing infantry targets with a single shot, and heavily damaging those in the immediate vicinity of where the round impacts. Its intended usage is similar to that of a [[M39 rocket turret]], though the rocket turret does not possess the all-around utility and adaptability of the M68 ALIM and causes much more collateral damage.

===Advantages===
The M68 is an extremely accurate weapon, useful against most enemy infantry and vehicle units. Unsurprisingly it has proven to be devastating against light-armored vehicles; it can take out a {{Pattern|Karo'etba|Ghost}} or a [[Banshee]] in one or two shots (depending on shot placement). The weapon is rather effective against Wraiths as well, provided the driver can out-flank the Wraith and fire upon its unprotected backside before it brings its [[plasma mortar]] to bear. Firing at the vehicle's armored front is less effective, but the rate at which the weapon cycles can compensate for this. The M68 is also very deadly if used against infantry, however users should aim at the most dangerous units like [[Sangheili]], [[Jiralhanae]] and [[Mgalekgolo]] in order to make full use of the weapon before moving onto smaller, less dangerous targets. Its relatively high rate of fire, when compared to other electromagnetic accelerator weapons, makes it a devastating precision weapon on any battlefield. Its anti-armor capabilities are second only to those of the [[SP42 Main Battle Tank|SP42 Cobra]]'s mounted [[M66 light rail gun]], and static defense platforms, such as the [[Mark 2488 Magnetic Accelerator Cannon|Onager]], and its portability more than makes up for this.

===Disadvantages===
The M68 has few disadvantages, mainly the fact that the weapon (like all other vehicle-mounted turrets) offers little to no protection to the operator, and allows them to be easily sniped without the presence of a skilled driver. It lacks precision at extreme distances, but can still hit large targets (i.e. Wraiths and Phantoms) with a fair degree of accuracy. The Gauss Cannon can also cause permanent hearing damage when fired within 20 meters of unprotected infantry.{{Ref/Reuse|ENC}}  The M68's muzzle flash can also give away its user's position. {{Ref/Reuse|H4VG}}

==Tactics==
*The M68 is (unsurprisingly) an excellent anti-vehicle weapon. It will get rid of enemy light armor rather quickly.
*While not as effective against entire squads, it remains good against single infantry units.
*Outstanding against [[Deutoros-pattern Scarab|Scarab]]s in ''[[Halo 3]]'', since the Warthog on which the weapon is mounted is a smaller, faster target for it to hit. An effective tactic is to remain under the Scarab, avoiding the legs and the main gun, while your [[UNSC Marine Corps|Marine]] gunner targets the Scarab's legs. Doing this with a co-op player is even more effective.
*Experienced gunners using this weapon can effectively use the cannon's extremely high damage and accuracy to 1-shot kill most enemies. This has led to many Gauss gunners being able to attain high multi-kills and [[Killing Spree Medal|killing sprees]], especially in [[multiplayer]]. Perfections are also not unheard of, especially if the hog the cannon is mounted on is parked away from the main battlefield.

==Changes==
===Changes from ''Halo 3'' and ''Halo 3: ODST'' to ''Halo 4''===
*Rate of fire reduced considerably
*Faster turn rate
*Sharper firing sound
*Increased damage and AoE damage.

==Trivia==
===Miscellaneous===
*While operating on a similar principle to the [[M99 Stanchion]], the shells for the M68 appear to be designed to cause [[wikipedia:Hypervelocity|hypervelocity]] collisions, where the target and slug get almost entirely vaporized on impact. This is probably intended to reduce over-penetration.
*In ''Halo 3'', the screen on the cannon's firing mechanism will actually display its surroundings in real-time thermal imaging, similar to the scope of the [[Sniper Rifle System 99D-S2 Anti-Matériel]]. Unfortunately, this does not have any effect on gameplay, and is only in place for aesthetic reasons.
*In ''Halo 3'', the slug in mid-flight is blue with a blue tail, making it look like Covenant weapon's fire at first glance. This 'blue light' is most likely the slug heating the air around it to super heated levels due to friction with the atmosphere. In ''Halo 2'', the trail was yellow-orange.
*Despite being called a "Gauss Cannon", the weapon is instead a coilgun, having none of the operational mechanisms characteristic of an actual Gauss Cannon. 

===Production notes===
*During the ''Halo 2'' demo trailer, the Gauss fired at a fairly rapid speed. Later, in an early beta multiplayer phase the M68 seemed to be slowed down and also seemed to have lost all its hype. It was later revamped with its original rate of fire during the game's final stages.
*The ''Halo 3'' version of the Gauss Cannon is a bit weaker and has a slower rate of fire than its ''Halo 2'' version. Part of this reason is gameplay balance since the ''Halo 2'' version was allegedly claimed to be too powerful in-game.
*Though to be similar to the [[LRG Rail Gun]], the primary armament of the [[Cobra]] artillery vehicle seen in ''[[Halo Wars]]'', the Gauss Cannon actually functions on a completely different principle. A [[railgun]] simply uses an electrical current to force a magnetic projectile along using the principle of same-pole repulsion; a more complex coilgun, or Gauss gun as it is known in Halo, uses multiple coils to accelerate the projectile through the weapon.

==Gallery==
{{linkbox|gallery=yes}}
<gallery>
File:H2-M68ALIM-GaussCannon.png|The M68 ALIM in ''Halo 2''.
File:H2-GaussHUD.png|HUD of the M68 in ''Halo 2''.
File:Ammo -Gauss.png|A Gauss slug of the M68 Gauss cannon from ''[[The Art of Halo 3]]''.
File:Halo3GaussHogLastResort.jpg|A Gauss Warthog on [[Last Resort]] in ''Halo 3''.
File:H3-GaussHUD.png|HUD of the M68 in ''Halo 3''.
File:Gauss turret.png|The M68 ALIM in ''Halo 3''.
File:Gaussshot.jpg|A closeup of a Gauss cannon's projectile in the air. Note that the contrail starts out blue but fades to yellow in ''Halo 3''.
File:HTMCC-H3 Dubbo on a Gauss Hog.jpg|A Marine fires a Gauss cannon in ''Halo 3''.
File:Old HW Gauss 2.png|John-117 firing a Gauss cannon in ''Halo 3''.
File:H3ODST-StationaryGauss-Reference.png|Turnaround reference image of the mounted stationary Gauss cannon in ''Halo 3: ODST''.
File:Stationary Gauss Cannon.JPG|The stationary variant of the Gauss cannon in ''Halo 3: ODST''.
File:H3ODST Rookie&GaussCannon.jpg|The [[Jonathan Doherty|Rookie]] inspecting a destroyed Gauss cannon in ''Halo 3: ODST''.
File:HTMCC-H3ODST Dutch M68.png|[[Taylor Miles]] manning a stationary Gauss cannon in ''Halo 3: ODST''.
File:HW-M12G1svsInnies.png|Gauss cannons in ''[[Halo Wars]]''.
</gallery>

==List of appearances==
*''[[Halo 2]]'' {{1st}}
*''[[Halo: Uprising]]''
*''[[Halo 3]]''
*''[[Halo Wars]]''
*''[[Halo 3: ODST]]''
*''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''
**''[[Palace Hotel]]''
*''[[Halo: Envoy]]''
*''[[Halo: Retribution]]'' {{Mo}}
*''[[Halo: Oblivion]]''
*''[[Halo: Hippocratica]]''

==Notes==
{{Ref/Notes}}

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

{{UNSC heavy weapons}}
[[Category:Magnetic acceleration weapons]]
[[Category:UNSC ground weapons]]