Editing BattleTech (section)

===The Mechs===
{{topquote|Shoot for his cockpit! [[Iron Hands|Kill the meat]], [[Adeptus Mechanicus|save the metal.]]|Sergeant Robert "Deadeye" Unther, ''MechWarrior 2: Mercenaries - Training Tutorial''}}
BattleTech 'Mechs function and are utilized more like tanks with legs than the super-agile flying mecha common in Japanese depictions. 'Mechs are deployed in formations of four or five, called lances in the Inner Sphere and stars in the Clans. They are able to operate in space, on planets with caustic atmospheres, underwater, and in a wide range of temperatures that would be lethal to unprotected humans. One of the biggest upsides of 'Mechs as combat vehicles is their extreme efficiency-of-arms: an effectively limitless amount of time without requiring fuel due to their fusion reactors alongside hyper-efficient Myomer 'muscles' inside the BattleMech’s limbs that can carry more weapons and armor per-ton than any other combat platform in existence. The only things stopping a 'Mech from being able to fight forever are ammunition, repairs, and allowing the pilot to rest. Even when a 'Mech is destroyed, losing the pilot is a relatively rare occurrence thanks to very effective ejection systems. A destroyed 'Mech chassis can also be salvaged and rebuilt to fight another day, good as new. In the early 3000s setting this means many 'Mechs are often decades or even hundreds of years old, Ship of Theseus-style. Some 'Mechs even have unique identities and/or affiliations with certain royal Houses or mercenary families. Also, as stated in the quote above, it's not uncommon for cash-strapped mercenaries, pirates, or even planetary militia to prioritize aiming for the cockpit and/or forcing MechWarriors to eject from overheating/battle damage in order to claim the surviving BattleMech wreckage for salvage or as a spoil of war.

As far as locomotion styles, bipedal 'Mechs are the most common, with the weapon systems mounted either in the torso compartments or on the arms. Quadrupedal 'Mechs do exist but are relatively rare, they are slower than bipedal 'Mechs and don't offer the same amount of weapon space for a given weight class and more legs (and more everything else) on a 'Mech means, of course, greater expenses. Even rarer are tripod 'Mechs, generally restricted to experimental super-heavy designs. Bipedal 'Mechs can also grasp things in their hands (if they have them) like melee weapons or pesky tanks. Early versions of BattleTech feature 'Mechs that could transform into fighter planes, but these were dropped relatively quickly in its life cycle due to copyright problems.

The main downside of 'Mechs is their inability to efficiently manage heat buildup.  Heat is generated by the fusion reactor, the environment, movement, and mostly as a result of firing weapons.  'Mechs mount multiple gigantic one-ton heatsink units to deal with this buildup, but it is a constant problem for pilots to manage. 'Mechs that feature a lot of energy-based weapons will generate especially high levels of heat, and therefore manage very poorly in extremely hot environments. Firing all the weapons of certain 'Mech variants at once (the ''Nova'' 'Mech is most infamous) can cause it to overheat to such an extent that the reactor core melts down before the heatsinks can shunt the heat out of the chassis, which is bad.  Safety measures that shut down the entire 'Mech when it reaches a certain temperature threshold are always installed, but since this usually happens in a combat situation, and thus leaves the 'Mech defenseless, some pilots will intentionally disable the safeguards to take their chances.  Depending on the technology level of a given game, more efficient heatsinks can be assigned to 'Mechs that remove heat more quickly and allow hotter builds. The fluff also mentions some experimental heatsinks that changed the heat energy to light (<strike>???</strike>Actually plausible, we have been experimenting with this concept irl) but had the downside of making the 'Mech look like a walking rave, as well as heatsinks that utilized caustic liquids to move heat faster but with a limited lifespan.  

Weapons consist of three general categories: ballistic, energy, and missile. Each has its own strengths and weakness: ballistic weapons weigh more, require ammo, but do not generate much heat, energy weapons are the opposite, and missiles generate some heat/consume ammo but can be indirectly fired with targeting data from scouts. Outfitting a 'Mech for the proper engagement is key to obtaining victory: 'Mechs outfitted for 'Mech-to-'Mech combat will generally mount only high-damage weapons with lower ammo counts and slower rates of fire, while 'Mechs set for vehicle and infantry combat will mount weapons that fire quickly but do lower damage per shot. Likewise, 'Mechs that do not expect steady resupply will mount more energy weapons so they are not beholden to ammo counts.

BattleMechs range between 20 to 100 tons in four weight classes, though a few experimental units lie outside these ranges. The weight classes are light (20-35 tons), medium (40-55 tons), heavy (60-75 tons), and assault (80-100 tons). Considering their size (23-56 feet), that's pretty light; the Maus (33 feet long and 11 feet high) mega-tank that Adolf Hitler demanded weighed 188 tons. (One possible explanation here is that the "tonnage" in a weight class isn't the weight of the 'Mech, but rather the weight available to mount things on the chassis. So an Atlas assault 'Mech has 100 tons of available space for reactor, life support, weapons, armor etc, explaining why various sub-types of a 'Mech drop something and replace it with something else of equal weight. A Flea light 'Mech has 20 tons). Rarer still are super heavy 'Mechs (with weights between 110 to 200 tons). While they are walking fortresses that put even Assault Mechs to shame, they tend to be ridiculously expensive, extremely slow, have issues with supporting that weight, are vulnerable to attacks from swarms of smaller enemies like tanks, and have difficulty installing reactors with sufficient power. Top sustainable speeds of 'Mechs vary from 32.4 kph (20 mph) for the assault ''Annihilator'' to 162 kph (101 mph) for the light ''Firemoth'' scout. Keep in mind that the American M1A1 Abrams tank has a top speed of 72 kph (45 mph) on a paved road and much less crossing difficult terrain. 'Mechs can also be mounted with rechargeable jump jets that give them the ability to hop across the battlefield or up/down terrain. According to varying fluff depictions, 'Mechs are even able to climb up/down cliff walls and perform flying dropkicks to enemy cockpits, which is [[awesome]].

Depending on where in the timeline the specific game takes place (this is a player choice), there will be two possible classes of mechs: [[BattleMech]]s and [[OmniMech]]s. BattleMechs are the older style, with a set number of variants that cannot be changed in the field.  This style was universal in the Inner Sphere before the arrival of the Clans. OmniMechs, a Clan invention, feature a modular construction style and a snap-on software integration which gives them the freedom of changing loadouts quickly. For example, a ''Dragon'' BattleMech comes in a default configuration consisting of one LRM-10, one Autocannon/5, and two medium lasers. The -1C variant replaces the Autocannon/5 with an Autocannon/2 and more armor, while the -5N upgrades the Autocannon/5 to an Ultra Autocannon/5. A pilot must use one of these variants and is incapable of changing the loadout without serious hours-long reworking of the 'Mech's internals in a 'Mech maintenance facility. Conversely, a ''Mad Dog'' OmniMech comes with a default configuration of two LRM-20s, two medium pulse lasers, and two large pulse lasers. A pilot is able to modify this loadout as they see fit within less than an hour with a technical team, say dropping the two medium pulse lasers for more missile ammo/armor or changing the LRMs to SRMs for short-range engagements.

Like most Western sci-fi series, BattleMechs are somewhat inspired by real theoretical technologies; their weapons range from machine guns (albeit very big ones) and missiles, to coilguns and particle accelerators. The biggest leaps from reality (aside from FTL travel and communications) are the fusion reactor, (a technology still only theoretically possible,) the neurohelmet, (which interfaces with the pilot's brain and keeps the 'Mech upright based on the pilot's own sense of balance,) and the massive muscle-like Myomer fibers that actually allow the 'Mech to move upon being exposed to electrical current.

While BattleMechs dominate the battlefields of BattleTech, armored vehicles still have a place. Most of the time, tanks, hovercraft, and APCs are used where 'Mechs would be too expensive (or too advanced) to maintain, or in roles where a 'Mech would be ineffective. This means that, in addition to BattleMechs, one can find infantry, vehicles, aerial vehicles, naval vehicles, and spaceships. It is worth noting that vehicles can be a real threat to BattleMechs in great enough numbers, since they mount the same weapons as 'Mechs.  Some tanks can also push the 100-ton limit and sport the gigantic weaponry usually mounted on an Assault 'Mech chassis. In other words, where 'Mechs are [[Space Marines]], the vehicles are more akin to [[Eldar]] Aspects.

BattleMechs in BattleTech fiction also have a curious tendency to go up in a mini nuclear explosion when their reactor core is breached by weapon fire. Mushroom clouds, explosions, heat, radiation, the whole bit. This has been nicknamed "stackpoling" after BattleTech novel author Michael Stackpole, who includes at least one of these events in each novel he writes. If the reactor was actually breached, what should happen is a meltdown of the reactor (and probably some chunks of the surrounding 'Mech) that quickly burns out because the reactor can't maintain the fusion reaction without proper containment. Reactors are generally incapable of generating an actual nuclear explosion: real-world reactor "explosions" are usually a result of the coolant flash-overheating and generating a pressure-based steam explosion that destroys the reactor building.  Lingering radiation would still be a problem of course, but that is usually handwaved away in BattleTech fluff or not mentioned at all. 

To get into the actual science of this, a hypothetical fusion reactor wouldn't produce that many radioactive substances. And what few they do would be relatively short lived and would be weak beta emitters. The most likely substance would be Tritium, which is where the stereotypical glow in the dark green radiation comes from. The 'Mech would glow in the dark but a decent decontamination process would render it mostly harmless. In other words, the stories are right for the wrong reasons.

More on actual science. A containment breach would produce a pretty big explosion. The reactor (assuming H+H fusion, which seems reasonable since we never hear anything about deuterium or H3 mining) would be operating at something close to 15,000,000K temperature and 250,000,000,000 atmospheres of pressure to induce fusion. Assuming there's a couple of cubic meters of gas being contained at those pressures by magnetic fields and surrounded by a few more cubic meters of vacuum, a sudden and catastrophic loss of containment would almost certainly cause an explosion that would cause a mushroom cloud and be easy to mistake for a small nuclear weapon.