The basic changes to Dungeons and Dragons 5e.
Strength - Used for feats of physical force, as well as using machineguns. Certain equipment such as heavy armour is restricted to certain Strength thresholds.
Dexterity - Used for evading attacks and shooting most guns.
Constitution - Used to endure damage as well as resist effects such as stun grenades and EMPs, as well as for sustaining long distance movement.
Intelligence - Used to assess situations accurately and grant advantages in combat. Will also be used in future supplements for cyberwarfare.
Wisdom - Used to resist unusual conditions, as well as provide useful field skills.
Charisma - Used to lead other T-Dolls, as well as interact with both T-Dolls and humans.
Armour is a mechanic that allows a creature to reduce the amount of damage it takes. Certain creatures, classes and items will have the property of "Armour X", where X is the armour value.
Armour is cumulative, and applied to incoming damage before applying the effects of resistances and vulnerabilities.
Armour Piercing is a modifier applied to certain sources of damage, and is written as "Armour Piercing X" or "APX".
NTW-20 fires at an Aegis unit, and rolls 6 total damage. If the Aegis has Armour 4, it would reduce the damage by 4 to a total of 2. However, NTW-20's weapon has Armour Piercing 12, allowing it to ignore up to 12 levels of Armour, bypassing the Aegis' Armour 4 and doing the full 6 points of damage. The extra 8 points of Armour Piercing have no additional effect.
Designer's Note: Armour is a mechanic that could potentially introduce levels of clunkiness to a game of D&D due to the additional steps taken when resolving damage. However, a single character or creature's Armour and Armour Piercing values will remain largely consistent throughout an encounter, and can be comfortably tracked in a similar manner to initiative, AC, passive perception, passive investigation and stealth rolls.
This is due to most creatures having static values for Armour and AP that are only changed upon level-up, and only a single type of standard attack.
These rules are a variant on the damage to object rules.
Certain objects such as bullet-resistant glass or reinforced walls are designed to impair the passage of projectile weapons. Additionally, many weapons are designed to puncture walls and the like, wounding or killing those who hide behind them.
A DM should assign Armour values to objects in addition to AC and hit points. This will make certain objects much more resistant to most normal attacks. As usual, a DM may rule that an object is practically impenetrable, and cannot be penetrated or destroyed without specialized equipment.
For example, a brittle but hard object would have low hit points and low Armour, but high AC. A more absorbent object would have lower AC but higher hit points and Armour. A thick, soft object might have high hit points but low Armour and AC.
A DM may also wish to reduce an object's Armour level based on the damage it has sustained, but it can also be ruled that an object is only ineffective when it is reduced to 0 hit points. Another option is to apply a reduction to Armour at half hit points, or other thresholds.
Creatures hiding behind cover can become exceedingly difficult to hit. However, many rounds are designed to penetrate cover and hit the creature hiding behind it.
Again, NTW-20 is shooting a Jager. However, this time, the Jager is hiding behind a car door, providing it with half cover. NTW-20 has AP 12, and reckons that it will be easy for her to penetrate the door and hit the creature behind it. Thanks to the easier target, she hits, and rolls 9 damage. The DM rules that the door has Armour 2, reducing the damage by 4. NTW-20's AP 12 easily bypasses such paltry resistance, dealing the full 9 damage to the Jager.