Another good one. More have been added since I first seen them printed.
Last but not the least, Murphy was a grunt!
Murphy's Laws of Combat
1. You are not Superman.
2. If it's stupid but it works, it isn't stupid.
3. Never draw fire; it irritates everyone around you.
4. Odd or conspicuous objects attract fire. Never lurk behind one.
5. Armored vehicles are bullet magnets.
6. Incoming fire has the right of way.
7. It's not the one with your name on it; it's the one addressed "to whom it may concern" you've got to think about.
8. The only thing more accurate than incoming enemy fire is incoming friendly fire.
9. Tracers work both ways.
10. If the enemy is in range, so are you.
11. If the sergeant can see you, so can the enemy.
12. Those who hesitate under fire usually do not end up KIA or WIA.
13. There is nothing more satisfying than having someone take a shot at you, and miss.
14. Avoid loud noises; there are few silent killers in a combat zone.
15. One enemy soldier is never enough, but two is entirely too many.
16. Try to look unimportant. The enemy may be low on ammo.
17. When in doubt, empty your magazine. Ammo is cheap; your life isn't.
18. It is physically impossible to carry too much ammo.
19. Teamwork is essential; it gives them someone else to shoot at.
20. Never share a foxhole with anyone braver than you are.
21. When you have secured an area, don't forget to tell the enemy.
22. No battle plan ever survives contact with the enemy.
23. There is always a way, and it usually doesn't work.
24. The important things are always simple.
25. The simple things are always hard.
26. The easy way is always mined.
27. The Cavalry doesn't always come to the rescue.
28. Combat will occur on the ground between two adjoining maps.
29. If only one solution can be found for a field problem, then it is usually a stupid solution.
30. You can win without fighting, but it's a lot tougher to do. And the enemy may not cooperate.
31. Once you open a can of worms, the only way to recan them is to use a larger can.
32. In crises that force people to choose among alternative courses of action, most people will choose the worst one possible.
33. Every man has a scheme that will not work.
34. For every action, there is an equal and opposite criticism.
35. Everything goes wrong at once.
36. Anything you do can get you shot, including doing nothing.
37. If your attack is going really well, it's an ambush.
38. If your flank march is going well, the enemy expects you to outflank him.
39. The enemy diversion you're ignoring is the main attack.
40. When an error has been detected and corrected, it will be found to have been correct in the first place.
41. If your positions are firmly set and you are prepared to take the enemy assault on, he will bypass you.
42. If your ambush is properly set, the enemy won't walk into it.
43. A retreating enemy is probably just falling back to regroup.
44. After things have gone from bad to worse, the cycle will repeat itself.
45. Fortify your front; you'll get your rear shot up.
46. Almost anything is easier to get into than out of.
47. If you make it too tough for the enemy to get in, you can't get out.
48. Nothing ever goes away.
49. No matter which way you have to march, it's always uphill.
50. If you are forward of your position, your artillery will fall short.
51. A grenade with a seven-second fuse will always burn down in four seconds.
52. The only time suppressive fire works is when it is used on abandoned positions.
53. When in a firefight, kill as many as you can; the one you miss may not miss tomorrow.
54. The only terrain that is truly controlled is the terrain upon which you are standing.
55. If at first you don't succeed, call in an air-strike.
56. Cluster bombing from B-52s and C-130s is very, very accurate. The bombs always hit the ground.
57. B-52s are the ultimate close support weapon.
58. The best tank killer is another tank. Therefore tanks are always fighting each other, and have no time to help the infantry.
59. The law of the bayonet says the man with the bullet wins.
60. Napalm is an area support weapon.
61. Mines are equal opportunity weapons.
62. If you can't remember where you put it, the claymore is pointed at you.
63. No combat-ready unit ever passed inspection.
64. No inspection-ready unit has ever passed combat.
65. The side with the fanciest uniforms loses.
66. Beer math: two beers times 37 men equal 49 cases.
67. Body count math: 2 guerrillas + 1 probable + 2 pigs = 37 enemy KIA.
68. If you take more than your share of objectives, you will be assigned more objectives to take.
69. When both sides are convinced that they are about to lose, they are both right.
70. Professional soldiers are predictable, but the world is full of amateurs.
71. Friendly fire isn't.
72. Recoilless rifles aren't.
73. Suppressive fire won't.
74. Interchangable parts aren't.
75. Guided missiles aren't.
76. Perfect plans aren't.
77. Final Protective Fire doesn't.
78. All-weather close air support doesn't work in bad weather.
79. Precision bombing is normally accurate to within plus/minus one mile.
80. Radios will fail as soon as you desperately need fire support.
81. Radar tends to fail at night and in bad weather, and especially during both.
82. When you've written down several of radio frequencies, the most important ones will be illegible.
83. Military Intelligence is a contradiction.
84. Every command which can be misunderstood, will be.
85. The crucial round is a dud.
86. The one item you need is always in short supply.
87. Things which must be shipped together as a set, aren't.
88. Things that must work together, can't be carried to the field that way.
89. The most delicate component will be dropped.
90. Design flaws travel in groups.
91. Tolerances accumulate unidirectionally toward maximum difficulty.
92. Nature sides with the hidden flaw.
93. If you mess with a thing long enough, it'll break.
94. Always keep in mind that your weapon was made by the lowest bidder.
95. The more the weapon costs, the farther away you will have to send it to be repaired.
96. If it jams, force it. If it breaks, it needed replacing anyway.
97. It is impossible to make anything foolproof because fools are so ingenious.
98. If enough data is collected, a board of inquiry can prove anything.
99. The enemy never takes notice until you make a mistake.
100. The enemy never monitors your radio frequency until you broadcast on an unsecured channel.
101. The enemy invariably attacks on two occasions: (a.) When you're ready for them; (b.) When you're not ready for them.
102. When you have plenty of supplies and ammo, the enemy takes weeks to attack. When you're low on both, they'll attack that night.
103. If you are short of everything except the enemy, you are in combat.
104. REMFs (Rear Echelon Mother Fuckers) are everywhere.
105. The quartermaster has only two sizes, too large and too small.
106. The most dangerous thing in the world is a Second Lieutenant with a map and a compass.
107. A man with one watch knows what time it is. A man with two watches is never sure.
108. If you really need an officer in a hurry, take a nap.
109. Never tell the Platoon Sergeant you have nothing to do.
110. Never stand when you can sit, never sit when you can lie down, never stay awake when you can sleep.
111. Don't ever be the first, don't ever be the last and don't ever volunteer to do anything.
112. If you find yourself in front of your platoon, they know something you don't.
113. When a front-line soldier overhears two General Staff officers conferring, he has fallen back too far.
114. Whenever you lose contact with the enemy, look behind you.
115. A sucking chest wound is nature's way of telling you to slow down.
116. A Purple Heart just proves that were you smart enough to think of a plan, stupid enough to try it, and lucky enough to survive.
117. Flies high, it dies; low and slow, it'll go.
118. A bad ride is better than a good walk.
119. Walking point = sniper bait.
120. Sniper's motto: reach out and touch someone.
121. As soon as you mention something, if it's good, it goes away. If it's bad, it happens.
122. Once a job is fouled up, anything done to improve it only makes it worse.
123. The newest and least experienced soldier will usually win the Medal of Honor.
124. The seriousness of a wound is inversely proportional to the distance to any form of cover.
125. There is no such place as a convenient foxhole.
126. There is no such thing as an atheist in a foxhole.
127. Respect all religions in a combat zone; take no chances on where you may go if killed.
128. When you drop your equipment in a firefight, your ammo and grenades always fall farthest away, and your canteen always lands at your feet.
129. If you can't tell what's shooting at you, it's an .88.
130. The bursting radius of a grenade is always one foot greater than your jumping range.
131. When you have plenty of ammo, you never miss. When you're running low, you can't hit the broad side of a barn.
132. Weather ain't neutral.
133. A clean and dry set of BDU's is a magnet for mud and rain.
134. Your bivouac for the night is the spot where you got tired of marching that day.
135. The worse the weather, the more you are required to be out in it.
136. As soon as you are served hot chow in the field, it rains.
137. Success occurs when no one is looking; failure occurs when the General is watching.
138. The more stupid the leader is, the more important the missions he's ordered to carry out.
139. Any ship can be a minesweeper ... once.
140. A little ignorance can go a long way in the direction of maximum harm.
141. When all else fails, read the instructions.
142. The tough part about being an officer is that the troops don't know what they want, but they know for certain what they don't want.
143. Negative expectations yield negative results. Positive expectations yield negative results.
144. You never find a lost article until you replace it.
145. Opportunity always knocks at the least opportune moment.
146. Things will get worse before they will get better -- and who said things would get better?.
147. Any or all of the above combined.
Last but not the least, Murphy was a grunt!