Damage Systems

The damage system is altered significantly enough from RAW that it deserves its own dedicated page. It takes inspiration from the Savage Rifts stuff, albeit with a bit more gradation.

Damage Basics for the New World

Understanding the Terminology

Let's make sure we know how the different acronyms are used, first. When talking about damage types, we must distinguish between Damage and Damage Capacity. Weapons and attacks are rated by their damage type, while targets are rated by their damage capacity totals. In other words, a laser weapon is a MD attack (mega-damage), while the opponent's bory armour would be a MDC target (mega-damage capacity). When saying things like "MDC" we are referring to targets specifically, and not attacks. It's a simple mistake to make, but try to remember to differentiate between attacks and targets when you can.
Also remember that "Hit Points" (HPs) are essentially SDC over-flow. Unless specifically stated in the attack description, your HPs are not reduced until after your SDC is eliminated. When that happens, all excess SD is taken out of your HPs. Technically this makes them moire or less interchangeable, and as such any damage to HPs is effectively treated as if it we SD, in the tables further below.

New Damage Classes

Adding a new class of damage: Heavy MD, aka HMD. This new class applies to anything that would be considered "heavy mega-damage" (HMD) such as vehicles, etc. Similarly, attacks and weapons of anti-vehicular or greater power are "heavy mega-damage capacity" (HMDC) targets. And with a setting like Phase World, it may be required to add yet another higher class of damage called "Super-Heavy" MD, applied to things of a space ship or similar scale. It's on the sable below, but currently not really a thing in our games as nothing from Phase World has made an appearance.
When rolling damage, check the following for how the damage grades translate:

SD vs SDC = x1

SD vs anything mega- = x0

MD vs SDC or MDC = x1

MD vs HMDC = /10, round normal

MD vs SHMDC = x0

HMD vs SDC or MDC = x10

HMD vs HMDC = x1

HMD vs SHMDC = /10, round normal

SHMD vs SDC or MDC = x100

SHMD vs HMDC = x10

SHMD vs SHMDC = x1

Or for a more handy table format:

Type Rolled vs:	SDC	MDC	HMDC	SHMDC
SDC	x1	x0	x0	x0
MDC	x1	x1	/10	x0
HMDC	x10	x10	x1	/10
SHMDC	x100	x100	x10	x1

Converting Core Material

For armor, vehicles, and creatures/beings, let's keep it simple. If its RAW statblock has 200 or more MDC in any single location, then it is Heavy MDC (HMDC) in these rules. If it has less than 200 MDC at its toughest location, then it is regular MDC. Thus Power Armor and Robots and most vehicles will be HMDC, while most personal body armor will be minor MDC. Exceptions may be made on a case-by-case basis.
For weapons, it's a bit trickier. With ranged weapons, anything that uses the WP: Heavy Mega-Damage skill can be considered a HMD weapon. Otherwise most MDC small-arms and longarms from the books will remain regular MD weapons.
Applicable "Ancient" style weapons (vibro-weapons, for example) will pretty much all be regular MD, unless wielded by someone with Augmented PS (31 or higher), Robotic PS (21 or higher), or Supernatural PS (16 or higher). In such cases, use the natural damage attack outputs instead.
Any melee "natural" attack from Robotic or Supernatural attackers will do HMD if its listed damage has a multiplier of x10 or greater. FREX, A supernatural PS 31 power punch (listed as 1d4x10 MDC) does Heavy Mega-damage.
All full-size missiles and rockets are HMD unless they are already written as SD. Mini-missiles are all regular MD unless they have a multiplier of x10 or higher, in which case they are HMD.
If it's a vehicle-mounted weapon, it is usually determined by the vehicle it's mounted on, with exceptions based on stated uses.
Curiously, all spells, psionics, and attacks of a magical nature that do MD will curiously do identical damage regardless of if the target is minor or heavy. Thus a spell doing 1d6 MD will do the same vs body armor and space ships. Certain effects may differ on a case-by-case basis.
The end result is the amplification of damage (by reducing default xDC values across the board), which will make combat deadlier no matter which weapon is used. Getting shot by a MD weapon still sucks, but it is no longer the instant vaporization that we may be expecting from the old way. And a big tough vehicle with a single mounted laser can still hold entire towns hostage.

Damage Pass-Through Rules

(New as of August 2021)
Inspired by the Pass-Through rules from Rifter #30, we're using something similar but a bit more condensed. Basically, even if you're wearing mega-damage armor, some forms of attacks will still relay damage through to the wearer (you). The tougher the armor, the less pass-through.
The types of damaging attacks that deal pass-through are anything kinetic (impact, railguns, missiles, explosives, etc). When struck by an MD (includes HMD and SHMD, after applying related multiples) attack, a percentage of the rolled damage is passed to the wearer as SDC damage. The amount is based on the type of MDC armor worn by the victim:

Light armor (most non-enviro body armor): 50% of the rolled damage

Medium armor (most light enviro armor): 30% of the rolled damage

Heavy armor (everything else): 10% of the rolled damage

Power Armor: As heavy armor, but only kicks in after depletion of 50% or more of the hit location's MDC.

Vehicles: As heavy armor, applied to the occupants, but only when the attack is using armor-piercing anti-vehicular weapons (see below)

Once the base Pass-through is determined from the above table, there are a few special notes:

Armor-Piercing attacks do triple the base pass-through damage.

Explosions and Area-Affects can apply damage to multiple opponents.

Rail Guns do double the base pass-through damage.

Any multiples from combined options are cumulative (so the pass-through from an armor-piercing rail gun is x10!!).
A defender can choose to roll with impact to potentially halve the damage, but in doing so they will be knocked down, over, or off-balance (GM's choice based on the attack).

Healing Rules

I want healing to be simpler and more comic-book-ish. So here's my take on recovering your stuff.
Recovering HP and SDC: HP is wounds, while SDCs are literally just "combat points" and don't represent actual health loss. As such, HPs recover slowly, while SDC should recover pretty quickly. Recover rates are as follows:

Full evening of Rest: Recover your PE in lost SDC, and also 1d6 HPs per 6-8 hours of actual rest.

Medic-Assisted Recovery: (Requires successful skill roll) Per day of recovery, restore your PE + 2x Medic's skill roll in SDC, and also 3d6 HPs.

First Aid Skill: If successful, recover your PE in lost SDC, plus the acting character's final First Aid die roll, and also 1d4 lost HPs.

(will add more as needed)

Recovering Personal MDC: If you have natural MDC, it recovers as if it were Hit Points in the above examples.