BattleMech

BattleMechs are legged armored fighting vehicles in the BattleTech Universe. Standing between 8 and 14 meters tall and heavily armed and armored, they are the main heavy ground combat vehicles. A person who operates a BattleMech is known as a MechWarrior.

BattleMechs are what Starfleet Starships are to Star Trek, Lightsabers are to Star Wars and Space Marines are to Warhammer 40,000. They are the specific Battlefield Technology that the setting is named for.

BattleMech Systems

Weaponry

• Lasers: Basic directed energy weapon. They are fairly cheap, do fairly consistent damage and since they're powered by the mech's reactor they don't need ammo. That said while they do burn into your enemies' armor, they also generate waste heat.
• Autocannons: Abbreviated as AC. An enormous machine gun/cannon that fires explosive shells in short bursts. Autocannons have variable ammo caliber sizes and are mostly grouped into categories of default damage numbers. While they don't generate much heat and are often times much better at taking armor off a Mech, they're also dependent on their hard ranges of minimum distance, requiring a lot of maneuvering to make work.
  • Autocannon/2 - The sniper rifle of Autocannons. While it's next to useless in a close-range firefight, it's good at taking potshots from a distance that even LRMs can't reach. Almost anything that has one usually loads up on special munitions to offset the loss of damage.
  • Autocannon/5 - Arguably the first Autocannon ever made, it does respectable but not especially impressive damage at longer ranges, and can open just the right armor type in a pinch.
  • Autocannon/10 - The gold standard of Autocannons simply due to it's sheer utility; it can do some real damage, has a reasonable range, but critically it also has no minimum range that the MechWarrior has to consider when using it. Most 'Mechs that have an Autocannon will almost certainly default to this or any variant of it.
  • Autocannon/20 - The short-range, big damage variant. Can only shoot about a few hundred yards out, anything dumb enough to be in it's range is pretty much scrap if the Autocannon lands more than one hit.
• Particle Projector Cannons: The other standard Energy weapon, but generally much spicier than any Laser. A massive Cannon that fires a concentrated stream of ions and protons at a target at such velocity and strength that the Mech it's attached to experiences a kickback from it. The Mech that gets hit can experience serious electrical damage from the volley, and as such they are prized parts of any Mech it's attached to; rivalling Autocannons in terms of overall usefulness. The Mech it's attached to has inhibitors to prevent the cannon from frying it's own circuits, but some mad lads play dangerously and pull that particular thing off in dire straits to see what happens when they let the PPC really cook.
• Missiles: You know how these work; a big rocket full of boom comes straight down on your opponent's face. Most Mechs that have them have a dedicated platform designed to deliver the payload; from dedicated missile systems designed to be fired at short, medium, or long ranges aided by fire control systems, or simpler, fixed range missile launchers like the Arrow IV that are designed to even out the terrain of a particularly unlucky stretch of land. Very useful, but prone to jamming due to a reliance on computer tracking.
• Gauss Rifle: A Gauss Cannon that has been standardized with powerful electromagnets to shoot a solid metal melon straight into and more often than not through opposing mechs. It generates almost no heat and is quite powerful, but is incredibly energy intensive and often enormous, requiring Mechs to almost be built around that weight limitation rather than the Rifle around the Mech's limitations.
• Flamers: They're in BattleTech too! You use them for almost the exact same purpose as you would in another wargame; melting infantry. This is much less useful in BattleTech however given that almost nobody uses full-on infantry anymore, but it can be helpful to raise the heat of a Mech to intolerable levels. The Capellans later invented a variant called Plasma (no, not that one) which uses ionized & viscous foam bullets launched at infantry or light armor like modern white phosphorus oe napalm.
• Machine Guns: For killing squirrels. If you're in a mech primarily armed with these you're mostly just there to keep infantry tied up, or, and I'm sorry to have to break it to you now, you're in the Mech that's expected to die.

Other

• Myomer: A synthetic musculature which contracts in on itself when an electrical current is run through it. Apply 9-volt battery, kick foe in the 'nads.
• Engines: Your standard BattleMech is powered by a hydrogen burning Fusion Reactor. Most vehicles used Internal Combustion Engines, or odder engines like Fuel Cells, and Fission Reactors. Yes, the rare Mech actually used some of these too, but the Fusion Reactor was the default go-to here. Engines come in all shapes and sizes, though the easiest way to keep your Mech useful is to have an engine that doesn't take up too much valuable space.
• Gyros: Not a sandwich beloved by greeks, but a spinny hunk of high-tech metal that helps the 'Mech stay upright. Losing this means your 'Mech gets to lie down for an extended period of time, namely for the rest of the battle.
• Armor: The yang to weaponry's yin. Depending on the tech level you're playing at, can come in flavours ranging from plain ol' vanilla Standard to double-fudge FerroFibrous, caramel Laser Reflective and whatever demented flavour-of-the year that the New Avalon Institute of Science has come up with. Most Mech armor is ablative, meaning that it's designed to slough off when
• Jump Jets: Systems that make the 'Mech bounce along like little bunny Froo-froo. On 'Mechs, they're a fusion-rocket system, however vehicles and infantry sporting them usually use some sort of jet or chemical/liquid-rocket system. Weirder systems have been developed (think mechanical pogo-mounts). Yes, there is a Jump Jet equipped tank called the Kanga.
• Heat Sinks: Glorified radiators, Heat Sinks are mechanisms which deal with built up heat, which Mechs can quickly accumulate in combat. Firing lasers, getting hit by flamers, using Jump Jets and so forth can all build up heat which can damage the machine's system and cook a Mech Warrior alive. Double Heat Sinks are more effective than vanilla heat sinks but were also LosTech up until the 32nd century.
• Neurohelmets: At base, Neurohelmets allow the 'Mech to borrow the pilot's sense of balance. More advanced systems (generally LosTech or ClannerScum) could provide a VR simspace for the pilot and shunt sensor feeds right into the pilot's brain. Also serves as a security system, as they're keyed to the pilot's brainwaves.

Types of BattleMechs

The most common classification of BattleMechs in-universe is by weight. How it's actually calculated is up in the air, as it doesn't appear to take into account the complete weight of the vehicle (since many Mechs have almost 10-20% of their tonnage taken up by armor), but it's generally agreed upon that this is the optimal "weight" of a fully kitted out BattleMech.

• Ultralight Mechs: Any Mech under 20 tonnes. Most of them are effectively just aluminum eggs with legs used to patrol garrisons and colonies out in the boondocks with a glock attacked to a button. The difference between one of these and an IndustrialMech is very, very difficult to parse.
• Light Mechs: Mechs between 20 and 35 Tonnes. They are normally cheap, easy to deploy, fast and lightly armored and are used for Scouting, Raiding, or in some cases urban defense. In Universe they are usually the most common type of Mech known.
• Medium Mechs: Mechs between 40 and 55 Tonnes. Able to throw down better than a Light Mech while being faster and cheaper than a heavy. Also includes specialized support units. Mostly used for tactical needs on paper, but tend to be wildly flexible in purpose in practice. Many of the more useful and iconic mechs in the series are in this category if they aren't Heavy Mechs.
• Heavy Mechs: Mechs between 60 and 75 Tonnes. The workhorses of most armies, affordable heavy power while still being able to move faster than a truck heaving forward. Several of the most iconic mechs in the series are in this class.
• Assault Mechs: Mechs between 80 to 100 Tonnes. The heavy hitters; ponderous and pricey but durable with heavy weapons and armor to both take and dispense a serious beatdown. Unless you get a BNS-1S. Then people mock you.
• Ultra Heavy: Any Mech that is more than 100 Tonnes. Up until the 32nd century, the general consensus was that Mechs more than 100 Tonnes were basically laughably bad penis compensators. In the 32nd century people are beginning to make them work, but logistics keep them towards being thankful .

Other

Beyond weight, there are a few other specialized types of BattleMech, each with their own strengths and drawbacks.

• Bipedal: A mech with two legs, most common type; broken down into three separate subcategories such as Humanoid, Reverse Joint, and Digitigrade, however performance between the three is negligible as all three have both standout variants and regrettable variants alike.
• Tripodal: An experimental three-legged variant that's only rarely been used, even when the design idea gained traction in the 32nd century, only four mechs in the entire canon have ever used this variant.
• Quadropedal: A mech which has four legs instead of two. They have something of a bad reputation for allegedly requiring more crew and less armor. Are far less common than Bipedal Mechs, but are still fairly common as mobile fire-boats. Another transformable variant is "Quadvees" among Clan Hell's Horses that can change back and forth into tanks.
• Land Air Mechs: sometimes called LAMs. Basically a light mech that can transform from an Aerospace Fighter into a regular mech. They got invented during the Star League and were experimental reconnaissance units but got phased out due to being more fragile than regular fighters and mechs. Out of universe, Battletech developers decided it was too much effort to keep without lawsuits from Harmony Gold (as seen with the infamous "Unseen/Reseen" mech artwork from other IP's).
• OmniMech: the Lego/Swiss army knive variant of a regular Mech. Can change their loadouts as quickly as diapers' but are way more expensive.

Notable BattleMechs

Over the span of seven centuries there has been like a bajillion different makes and models of Battlemechs, most of which have at least a couple variants. As BattleMechs can last for centuries and are rather resilient things that can more often than not be at least partially salvaged, there are still plenty of vintage units out and kicking. For a comprehensive list, go to Sarna.

• UrbanMech
• Atlas
• Timber Wolf
• Catapult