Random Murhy's law:
Sells's Law: The first sample is always the best.

Selected Murhy's laws:
Cannon's Comment: If you tell the boss you were late for work because you had a flat tire, the next morning you will have a flat tire.
More Murhy's laws...
Babcock's Law: If it can be borrowed and it can be broken, you will borrow it and you will break it.
Bagdikian's Law of Editor's Speeches: The splendor of an editor's speech and the splendor of his newspaper are inversely related to the distance between the city in which he makes his speech and the city in which he publishes his paper.
Barber's Laws of Backpacking:
The integral of the gravitational potential taken around any loop trail you chose to hike always comes out positive.
Any stone in your boot always migrates against the pressure gradient to exactly the point of most pressure.
The weight of your pack increases in direct proportion to the amount of food you consume from it. If you run out of food, the pack weight goes on increasing anyway.
The number of stones in your boot is directly proportional to the number of hours you have been on the trail.
The difficulty of finding any given trail marker is directly proportional to the importance of the consequences of failing to find it.
The size of each of the stones in your boot is directly proportional to the number of hours you have been on the trail.
The remaining distance to your chosen campsite remains constant as twilight approaches.
The net weight of your boots is proportional to the cube of the number of hours you have been on the trail.
When you arrive at your chosen campsite, it is full.
If you take your boots off, you'll never get them back on again.
The local density of mosquitos is inversely proportional to your remaining repellent.
Barrett's Laws of Driving:
The vehicle in front of you is traveling slower than you are.
This lane ends in 500 feet.
Barr's Comment on Domestic Tranquility: On a beautiful day like this it's hard to believe anyone can be unhappy -- but we'll work on it.
Barth's Distinction: There are two types of people: those who divide people into two types, and those who don't.
Bartz's Law of Hokey Horsepuckery: The more ridiculous a belief system, the higher the probability of its success.
Forthoffer's Cynical Summary of Barzun's Laws:
That which has not yet been taught directly can never be taught directly.
If at first you don't succeed, you will never succeed.
Baxter's First Law: Government intervention in the free market always leads to a lower national standard of living.
Baxter's Second Law: The adoption of fractional gold reserves in a currency system always leads to depreciation, devaluation, demonetization and, ultimately, to complete destruction of that currency.
Baxter's Third Law: In a free market good money always drives bad money out of circulation.
Belle's Constant: The ratio of time involved in work to time available for work is usually about 0.6.
Benchley's Law: Anyone can do any amount of work, provided it isn't the work he is supposed to be doing at that moment.
Berkeley's Laws:
The world is more complicated than most of our theories make it out to be.
Ignorance is no excuse.
Most problems have either many answers or no answer. Only a few problems have a single answer.
An answer may be wrong, right, both, or neither. Most answers are partly right and partly wrong.
A chain of reasoning is no stronger than its weakest link.
A statement may be true independently of illogical reasoning.
Most general statements are false, including this one.
An exception TESTS a rule; it NEVER PROVES it.
The moment you have worked out an answer, start checking it -- it probably isn't right.
If there is an opportunity to make a mistake, sooner or later the mistake will be made.
Being sure mistakes will occur is a good frame of mind for catching them.
Check the answer you have worked out once more -- before you tell it to anybody.
Estimating a figure may be enough to catch an error.
Figures calculated in a rush are very hot; they should be allowed to cool off a little before being used; thus we will have a reasonable time to think about the figures and catch mistakes.
A great many problems do not have accurate answers, but do have approximate answers, from which sensible decisions can be made.
Berson's Corollary of Inverse Distances: The farther away from the entrance that you have to park, the closer the space vacated by the car that pulls away as you walk up to the door.
Bolton's Law of Ascending Budgets: Under current practices, both expenditures and revenues rise to meet each other, no matter which one may be in excess.
Boren's Laws of the Bureaucracy:
When in doubt, mumble.
When in trouble, delegate.
When in charge, ponder.