Rifts House Rules - Ability Scores

Rifts and house rules are inevitable in my mind. It feels a lot like the old days for D&D when systems were much more malleable than 4th or even 3rd edition. There are several areas where I feel  some changes make for a better game. One of the changes I have made is to ability scores.
Rifts has always been confusing as far as stats, bonuses, and when they apply, plus the method for rolling is odd. Humans roll 3d6 for each stat but if they score a 16,17, or 18 then they get to add an additional d6. I scrapped this for 4d6 drop the lowest. Rifts actually has some skills (Physical Skills) that can be selected to add to certain attributes, so if you want a Physical Strength of 20 it's easily accomplished by rolling a decent score and then choosing weightlifting, boxing, etc.during skill selection. One problem solved.
Nonhuman races roll differing amounts of dice  - Ogres might roll 4 or 5 dice for strength, Orcs might have 4d6 for Physical Endurance, Pixies might only roll 2d6 for strength - I'm fine with that approach and leave it as-is.
Now that stats are a little more "regular" let's get some decent modifiers for them. I pretty much adapted the d20 ability score modifiers wholesale. My players and I were familiar with them and they do make the full range of scores count for something. So PS of 10-11 = +0, 12-13 = +1, 14-15=+2, etc. A Physical Strength of 40 now has a +15 modifier - but to what?
Rifts has a somewhat arbitrary division when it comes to combat, the infamous "Mega-Damage".  The ideas is that some super-high-tech weapons and powerful magic just operate on a while different scale than conventional weapons like guns and swords. It's an important part of the setting as characters cause superhero levels of damage without technically having superpowers.
For some reason though it was decided that mega-damage guns don't work the same way as regular ones so the Physical Prowess bonus doesn't count when using MD weapons. This makes little sense to me and additionally it makes character abilities like a high Prowess  less important than equipment bonuses like a +1 for a laser sight. The game also forbids adding character strength bonuses to MD melee damage, instead referring to a chart for punching damage based on strength number and type - yes there is "regular" strength, "augmented" strength, and "supernatural" strength - which all kind of matrixes together to tell you whether you do 1d6 or 2d4 or some other slightly different amount of damage.
I scrapped all of that. PS (Physical Strength) adds its modifier to all HTH combat damage. PP (Physical Prowess) adds its modifier to all to-hit rolls and dodge and parry rolls. There, I fixed it.
IQ (Rifts version of Int) and PP both affect initiative rolls.
IQ adds to the base percentages for skills
Mental Endurance (ME) adds to saves vs. fear and magic
Physical Endurance (PE) adds to saves vs poison etc.
Mental Affinity (MA) [Charisma] adds to reaction adjustments
Pretty much what you would expect them to do based on D&D style modifiers.
One reason for adding the strength bonus to all damage is that a mega-damage sword does about the same damage as a D&D sword but the MD armor you have to cut through starts at about 50 points for almost anything and rapidly scales up from there. Rolling 1d8 to beat down 50 points takes a long time. Considering that many PC's will be in the 20+ strength bracket, adding a +5 or +10 to that really helps keep the game from dragging and actually promotes the more frequent use of HTH combat that the game background seems to suggest. It's also one less fiddly rule to worry about.
Adding the PP bonus to all to hit rolls also ensures that hitting isn't much of a problem when you have the 30 PP Juicer going against the 10 PP mercenary. Rifts uses opposed d20 rolls in HTH as the attacker rolls to hit and the defender rolls to parry, high score wins. Classes, skills, equipment, and race can all add various bonuses to attack and to parry so adding in one more bonus from PP doesn't really upset things.
In the end it was more natural to my (then) 3rd edition D&D crew to use these modifiers and it kept combat flowing a little more smoothly. I still wasn't satisfied though as combat  still confused some people as all PCs end up with multiple attacks and hit locations were still causing trouble. More on that tomorrow.