US Marine Corp Rules For Gun Fighting

Bring a gun. Preferably, bring at least two guns. Bring all of your friends who have guns. Bring their friends who have guns.
If you can, make friends with those on the crew served weapons. Bring them as well. Borrow money from them, it gives them an added incentive to protect you.
Anything worth shooting is worth shooting twice. Ammo is cheap. Life is expensive.
Only hits count. Close doesn't count. The only thing worse than a miss is a slow miss.
If your shooting stance is good, you're probably not moving fast enough nor using cover correctly.
Move away from your attacker. Distance is your friend. (Lateral and diagonal movement are preferred.)
If you can choose what to bring to a gunfight, bring a long gun and a friend with a long gun.
In ten years nobody will remember the details of caliber, stance, or tactics. They will only remember who lived and who didn't.
If you are not shooting, you should be communicating (calling for arty or air support), reloading, and running.
Accuracy is relative: most combat shooting is more dependent on "pucker factor" than the inherent accuracy of the gun.
Use a gun that works EVERY TIME. "All skill is in vain when an Angel pisses in the flintlock of your musket."
Someday someone may kill you with your own gun, but they should have to beat you to death with it because it is empty.
In combat, there are no rules, always cheat; always win. The only unfair fight is the one you lose.
Have a plan.
Have a back-up plan, because the first one won't work.
Have a back-up, back-up plan in case CentCom or SecDef finds the first two plans "unacceptable".
Use cover or concealment as much as possible. The only visible target should be in your gun sights.
Flank your adversary when possible. Protect your flank.
Don't drop your guard.
Always tactical load and threat scan 360 degrees.
Watch their hands. Hands kill. (In God we trust. Everyone else, keep your hands where I can see them).
Decide to be aggressive ENOUGH, quickly ENOUGH.
The faster you finish the fight, the less shot you will get.
Be polite. Be professional. But have a plan to kill everyone you meet.
Be courteous to everyone, friendly to no one.
Your number one Option for Personal Security is a lifelong commitment to avoidance, deterrence, and de-escalation.
Do not attend a gunfight with a handgun, the caliber of which does not start with a "4."

Army Rules for Gun Fighting

See USMC Rules to gun Fighting.
Add 60 to 90 days.
Hope the Marines already destroyed all meaningful resistance.

Navy Rules for Gun Fighting

Adopt an aggressive offshore posture.
Send in the Marines.
Drink Coffee and eat donuts.


Air Force Rules for Gun Fighting

Kiss the wife goodbye.
Drive to the base in your sports car.
Fly to target area, drop bombs, fly back to your home base.
BBQ some burgers and drink beer in your back yard.