To be completely honest, the rules are so screwed up that the game is basically unplayable in its default state. The core mechanics were built to be an alternative to AD&D 2nd edition, and they work okay for PFRPG (Palladium Fantasy RPG), and to a limited extent in the other low-power (standard damage or S.D. in Palladium products), but once you shift to the high-power titles (RIFTS, Robotech, Splicers, other mega-damage/M.D. settings) the systems just fall apart.
The ideas and core concepts backing the Palladium system are fairly solid, with lots of variation and some pretty involved settings, but the mechanics are just not adequate at all.
Here's an example:
You are falling off a very tall building, when you hit the ground you take S.D./hit point damage from the fall that scales to the distance travelled, so this works.
A car is falling from the same very high building, it takes S.D. that scales to the fall, but does NOT scale to the weight/size of the vehicle, so right there we already have a problem.
An advanced super heavy tank is falling from the building, it takes S.D. as above, but it is a M.D. structure, so unless the total damage from the fall exceeds 100 S.D./hitpoints, it takes NO DAMAGE. Now the mechanic is not functioning at all.
A demon is falling from the building, as a M.D. supernatural being it also only takes damage if the total exceeds 100 S.D. (and it must deal another 100 S.D. for each additional point of M.D.)
Here's the kicker: That tank has several hundred M.D., so even if the total damage from the fall is high enough to do some damage, it will be almost meaninglessly small, and the demon has potentially THOUSANDS of M.D., and regenerates several M.D. per second making the whole exercise pointless.
That is just one of the many ways that the core mechanics are broken, I could probably write a fairly substantial breakdown of what doesn't work in the game, but that would be several pages long.
Shadowrun's mechanics are very involved, but they actually work, Palladium's mechanics just don't.