I am working on RPG game in my off time and I thought it be nice to use real world physics to determine the actually damage of the weapons and reduction of the armor. I have yet to make to the reduction part.Here is what I have and I hope you can help. Thanks for your time in advance. Please correct me if I am wrong.

Hypothesis 1: Damage is done by kinetic energy transferring from one state to another.

Hypothesis 2: Damage Reduction is the ability that an item has to redirect/dissipate/disburse/displace kinetic energy away.

What I think I know:

Kinetic Energy, Force, Heat all play a part (as well as Air Resistance and Temperature)

I have the used the following Examples to try and get a viable number but I can't seem to make sense of it.

Bolt Action Rifle Bullet (Original)

Mass: .28 kg

Velocity: 933.29 m/s

Distance: 47.72 m

Kinetic Energy: 121,944.2314 joules

Force: 261.3212 newtons

Navy Rail Gun Projectile (I am sure Temperature has something to do here)

Mass: 11.7934 kg

Velocity: 3,833.505688 m/s

Distance: 1 km

Kinetic Energy: 86,656,522.5462 joules

Force: 45,210.0660 newtons

Long Sword

Mass: 1.8 kg

Velocity: 9.144 m/s

Distance: 0.3048 m

Kinetic Energy: 75.2515 joules

Force: 16.4592 newtons

Am I completely off base in my thinking or am I missing something major? Thanks again for your time on this.