Building an Anvil

The first thing an Anvil starts off with is the Mobility Base. The Mobility Base (alternatively chassis or legs) defines some important aspects of how the Anvil is constructed and how it operates on the battlefield.

First and most obviously: the chassis type. Mobility Bases come in six distinct flavours: Biped, Reverse-Joint (RJ), Quadruped, Tank, Wheel, and Hover. Each chassis grants the Anvil different capabilities over different types of terrain.

Mobility Bases also possess a load tolerance, which determines how much weight the Anvil can carry, and a speed value, which determines how fast the Anvil moves under nominal load. Generally-speaking, the heavier the Mobility Base, the greater its load capacity and the lower its speed.

Mobility Bases also influence the Anvil's ability to Dodge. Dodging allows Anvils to spend EN to avoid damage entirely and some Anvils are much better at it than others.
Next comes the Core. The Core is the centre of the Anvil and the most critical of all six Components. The Core houses the pilot, the fire control systems, the Generator, and the bulk of the Electronics.

All Cores have a number of Hardpoints, usually between 1 and 4, though some may have more. Hardpoints allow the Core to carry Parts (weapons and equipment).

Cores also influence the Anvil's ability to Block. Blocking allows Anvils to direct incoming damage to a specific location, effectively showing "their best side" to enemy attacks.
Next is the Electronics. The Electronics Component is effectively the "head" of the Anvil and it coordinates the Anvil's virtual capabilities.

The Electronics provide the Anvil with Virtual Offence/Defense (VO/D) capabilities, a measure of how robust the Anvil's systems are to resisting enemy ECM, electronic attacks, and jamming efforts.

All Electronics Components have a Refresh value. This value determines how much EN must be spent to clear the Anvil of Errors (status conditions).

The Electronics also influences an Anvil's ability to Intercept. Intercepting allows Anvils to disrupt enemy attacks before they hit, reducing the incoming damage or negating it entirely.
Then come the Arms, two Components split into Left Arm (LA) and Right Arm (RA). Arms are arguably the least critical of all six Components but grant the Anvil unparalleled flexibility (and are generally really cool).

Arms come in two flavours: Standard Arms and Weapon Arms. Standard Arms typically possess a hand and can function similarly to a giant human arm. Weapon Arms never possess a hand and are usually little more than an integrated weapon in place of a normal Arm, trading flexibility for raw firepower.

Arms always have an Agility value. This value determines how accurate the Anvil's Arm is when throwing and manipulating objects, using melee weapons, or conducting physical attacks or grapples. Generally-speaking, heavyweight Arms with high durability lack fine control while Arms with high Agility tend to be more fragile.

Arms also have Hardpoints, like the Core, though typically never more than 2. These Hardpoints can carry many Parts including some that cannot be mounted on the Core, such as shields.
Lastly, the Generator. Generators are sophisticated powerplants capable of powering the Anvil for hours at a time.

Generators both produce EN and store EN through EN Output and EN Capacity stats respectively. All Components except for the Generator cost some EN to operate and many Parts cost EN to activate. Balancing EN Drain with EN Output and EN Cost with EN Capacity is important for the Anvil to function correctly.

Generators also have a Heat Tolerance and a Cooling Type. Heat Tolerance measures how much Heat an Anvil can sustain before running the Generator too hot. The Cooling Type influences how fast the Anvil loses Heat and how the Anvil acts when overheating. There are three Cooling Types: Gas-Cooled, Liquid-Cooled, and Plasma-Cooled. Each has its strengths and weaknesses.

Finally, Generators carry an amount of Fuel with them. Fighting in a multiton war machine exhausts energy at high rates and this Fuel measures how long an Anvil can remain in combat status. If the Anvil runs out of Fuel, it will become sluggish and unresponsive, and if Fuel is not obtained soon after that, the Anvil will grind to a halt and shut down.
These are the six Components which make up an Anvil: Mobility Base, Core, Electronics, Right Arm, Left Arm, and Generator.
Anvils can operate in reduced capacities without any of these Components except for the Core. If the Core is removed or destroyed the Anvil cannot function.
There is also one "subcomponent," known as the FCS (fire control system). The FCS influences the Anvil's targeting capabilities such as optimal firing range and the maximum amount of trackable targets at once. While not a true Component (and thus not targetable or destructible), the FCS is an important aspect of the Anvil. Without one the Anvil might as well be fighting blind.
After the Anvil has been built it's time to load it up with Parts. Parts come in two flavours: weapons and equipment. Weapons are, obviously, weapons. Guns, swords, missiles, laser cannons, and the like fall under weapons. Equipment on the other hand constitutes everything else, such as radars, vision modules, appliqué armour, local network systems, and so on. Most Parts require a single Hardpoint.

Some Parts are considered to be fairly large even by Anvil standards. These Parts, listed as "Outsized," require 2 Hardpoints on the same Component for mounting.

At the moment, weapons are broken into three broad classifications: Primary, Secondary, and Tertiary.

Primary weapons are usually fairly light and easy to handle, making up the bulk of the Anvil's firepower and offensive capabilities. Primary weapons can always be reloaded in the middle of battle.

Secondary weapons are usually heavy and can be bulky but fill out the Anvil's combat prowess by covering weaknesses or accentuating strengths. Secondary weapons can only be reloaded outside of combat.

Tertiary weapons are usually the lightest and easiest weapons to load but are limited in scope and ability, usually being "one shot." Tertiary weapons cannot be reloaded when spent and must be replaced.

Anvils can carry up to two Primary, two Secondary, and six Tertiary weapons, for a total of 10 weapons on any given frame.
There's another stipulation to that however: Hangar weapons. All Anvils past Gen 0 can carry weapons on or inside their Mobility Base, holstered in some fashion. Striding Mobility Bases (Biped/RJ/Quad) can only take weapons marked with an (H) in their Hangars while vehicular Mobility Bases (Tank/Wheel/Hover) can carry anything as long as it's not Outsized.
This means a Tank type could carry four Primary weapons (two in-hand and two inside the Mobility Base) but can only mount and fire two at any given time