Just some laws I thought of that have been inspired by the Murphy's laws for combat operations. Post your own!

"Enemy snipers can shoot the wings off a fly at 80 yards while drunk, yours couldn't hit the broad side of a barn"

"Enemy tanks are practically extensions of their commanders, your tanks are driven by drunkards"

"Enemy troops are reincarnations of Sun-tzu, Rambo and a hint of godzilla, your troops are chickens wearing very well made disguises"

"The enemy has a budget for infinite squads. You have a budget for three squads."

"Your favorite and/or best unit will always die near the end of any mission that has been particulary challenging."

The only thing more accurate than friendly fire is enemy artillery.

(Stolen from Half-Life: Opposing Force:)

If your attack is going really well, it's an ambush.

When both sides are convinced that they are about to lose, they are both right.

When you have secured an area, don't forget to tell the enemy.

No plan survives the first contact intact.