Ideas on rules that change the way the system is played, that have yet to filter into the core section as options.
Edge Protection: A refinement of 'flexible' armor types that converts some edged damage to crushing (even an indestructible shirt still transfers blunt-force trauma).
Toughness: A form of damage resistance that simulates an entity's resistance to blunt force without reducing the amount of harm from edged weaponry nearly as much.
Drop Excess Combat Info from Defense Evaluation: In other words, worry about defending BEFORE you know for certain the attack is going to hit you, instead of afterwards. Most relevant in gunfights, but also relevant elsewhere.
Rule of 14: For passive skill usage - assuming a roll of 14 covers 90% of the possible outcomes.