The system of Penetration Value (PV) in HU2 presented in The Compendium of Contemprary Weapons is not complete, but it's a good start towards improving the standard combat rules. Anyone playing a firearms-driven character should definitely purchase (and make use) of this book, as it adds great context to the Palladium combat system. Unfortunately, even with this addition, there are a few severe flaws in the standard combat rules:
My goal is to create a set of rules that can be easily committed to memory, yet deals with a wide range of situations. This revised, expanded system is meant to be megaversal (ie, applicable to all Palladium settings), allowing realistic interaction between SDC and MDC items. Finally, it seems advantageous to make a system that can be used by different gaming groups on different levels. Some people like to follow each bullet in incredible detail, while others just want to roll damage and move on. Ideally, this revision will be scalable to please the full range of gamers between these extremes.
What I present on the following pages is subject to frequent and significant change right now, as the system is still in development. E-mail me if you have any input, and be sure to check back if you see any incomplete sections that interest you. Most of all, I hope you'll let me know how things work out if you implement any of this system during a game.
The first step: Introduce an analog to Penetration Value called Penetration Resistance (PR), describing the resistance of a given thickness of armor to penetration. A system of applying damage from weapons with known PV to armor with known PR is developed, and specific examples of the interaction between various SD firearms and structures are presented. With this new information, it is also necesary to revisit the issues of Armor Coverage when dealing with body armor, both SDC and MDC.
The abilities available in HU2 must be related to the penetrative value of modern firearms. From here, the system of assigning PV easily extends to Mega-Damage (MD) weapons and attacks. One important consideration is how highly penetrative energy weapons will interact with less resistant structures.
In the end, my goal of more realistically determining damage due to penetration of rounds through armor seems to be served. The system scales up from tiny puffs of fire to armor-piercing anti-tank weaponry, and even to MD weaponry. Interaction between weapons and armor at all levels is governed by a set of straightforward rules. The tradeoff to this system is that an electronic calculator will be required to calculate the fractions of unmodified damage.
This system seems to encourage using appropriate ammunition for a given target. Bullets with high PV may actually do less damage to a human target than those with a low PV. Ammunition with a PV of 4 is optimal for use against human targets, while higher PV rounds are appropriate for armored structures. The system also allows for the "overhead cost" of using a low penetration round against an armored structure.
If players want a more realistic system, allowing them to "follow the bullet," this seems to supply a framework. The level of detail a GM wishes to go into is very flexible; it is possible to declare that a bullet has stopped at any point along its trajectory, depending on the wishes of the GM. This allows the system to be balanced for time consumption and gameplay considerations without significant alteration.
One thing I like about this system is that it encourages players to think about the weight of their armor, especially in MDC environments. MDC material only seems to have 10 times the damage capacity of comparable SDC material, but MD weapons are 100 times more damaging than their SD counterparts. This means that armor has to be much thicker in an MDC world. Looking at the pictures of body armor in the Rifts Main Book tells me that armor thickness has indeed been increased. A glance at the DeadBoy armor worn by the Proseks on page 192 leads me to estimate a thickness between 1½ and 2 inches on the main body. This corresponds, on my table of thickness vs PR, to armor with PR between 24 and 25. I may be over-estimating, but keep in mind that most of the armor is curved, and an attack will have to cut through the armor at an angle. This lends the armor an effective increase in thickness.