Some rules from my GM that he's implemented in our current 4e game (the rules have been adjustable as we try things and either like them or hate them). We have more, but they are more complicated and still not agreed has being "good" (mostly trying to fix how things work in the matrix between hackers, technos, and AI).
"Spellcasting is now broken up per school of spell (combat/health,etc), and specilizations must be made for each skill and be more specific (i.e. Combat Casting specilized in fire spells)."
"Karma Purchasing will stage over time. The cost (value) of Karma will be 100 nuyen times the number of karma awarded to the character with a maximum of 4 karma purchased per karma earned. This will slow the progressions a bit." - This was needed as we wanted to have bigger monetary awards for our game to allow for purchase of bigger toys to support global running, admitadley not the best rule for every game.
"Rather than rolling Program+Skill, Matrix actions will treat Programs and Complex forms similar to spells, their rating will limit the maximum number of applicable success. (Note, Attack Programs are already treated like combat spells)
Rolls will be Attribute+Skill+Appropriate Modifiers with a Maximum of the Program Rating
Results in requiring hackers to be mental heavy like AI and Technomancers. Better balance between the three.
Armor and Biofeedback Filter are exceptions to this rule, they continue to mechanically function like armor
Program/Complex Forms can be rushed, trading Rating for bonus dice on a one-for-one basis. "
"All Armor now counts as “hardened armor” equal to HALF the armor’s modified value, round down. This applies ONLY to the highest armor value of all stacked armor sources.
Hardened Armor rules now apply BEFORE rolling attack.
AP is subtracted from hardness directly, not subtracted from Armor before the Divide by Two
Together this means that someone in heavy military armor, rating 16, has a hardened value of 8. This means that it takes a weapon with a base damage (before rolls and multiple shots) plus armor piercing of 8 to even have a chance of hurting him. Only heavy automatic weapons will get past this level of protection.
Armor can still be bypassed with a called shot. In the above example this target would need either a big gun like an assault cannon, heavy machine gun, or sniper rifle, or an extremely good gunner to hurt the target.
Stun vs Physical Damage is still handled after the attack roll. So it is still unlikely for a heavy machine gun with normal rounds to hurt a tank with 20 armor with a single round. (Hardness 10 matched by damage 7 & -3 AP) but using AV Rounds the heavy machine gun can deal 16+ against the effect hardness 4 and armor 14. So the AV machine gun will hurt."