To the best I've been able to tell in 26 years of observation, this is how the Universe works. I hope I didn't leave anything out.
1a) Never throw shit at an armed man.
1b) Never stand next to someone who is throwing shit at an armed man.
You wouldn't think anyone would need to be told this. It dates from the Democratic National Convention of 1968.
2) Never fire a laser at a mirror.
3) Mother Nature doesn't care if you're having fun.
You will not be stopped! There are things you can't do because you burn sugar with oxygen, or your bones aren't strong enough, or you're a mammal, or human. Funny chemicals may kill you slow or quick, or ruin your brain ... or prolong your life. You can't fly like an eagle, nor yet like Daedalus, but you can fly. You're the only earthly life-form that can even begin to deal with jet lag. You can cheat. Nature doesn't care, but don't get caught.
4) Giving up freedom for security has begun to look naive.
Even to me. Many of you were ahead of me on this. Three out of four hijacked airplanes destroyed the World Trade Center and a piece of the Pentagon in 2001. How is it possible that those planes were taken using only five perps armed with knives? It was possible because all those hundreds of passengers had been carefully stripped of every possible weapon. We may want to reconsider this approach. It doesn't work in high schools either.
5) Psi and/or magical powers, if real, are nearly useless.
Over the lifetime of the human species we would otherwise have done something with them.
6) It is easier to destroy than create.
Bin Laden tore down the World Trade Center? Let's see him build one. If human beings didn't have a strong preference for creation, nothing would get built, ever.
7) Any damn fool can predict the past.
Military men are notorious for this, and certain writers too.
8) History never repeats itself.
9) Ethics change with technology.
10) Anarchy is the least stable of social structures.
It falls apart at a touch.
11) There is a time and place for tact.
And there are times when tact is entirely misplaced.
12) The ways of being human are bounded but infinite.
13) When your life starts to look like a soap opera, it's time to change the channel.
14) The only universal message in science fiction: There exist minds that think as well as you do, but differently.
Niven's corollary: The gene-tampered turkey you're talking to isn't necessarily one of them.
15) Fuzzy Pink Niven's Law: Never waste calories.
Potato chips, candy, whipped cream, or a hot fudge sundae may involve you, your dietician, your wardrobe, and other factors. But FP's Law implies: Don't eat soggy potato chips, or cheap candy, or fake whipped cream, or an inferior hot fudge sundae.
16) There is no cause so right that one cannot find a fool following it.
To prove a point, one may seek out a foolish Socialist, thirteenth century Liberal, Scientologist, High Frontier advocate, Mensa member, science fiction fan, Jim Bakker acolyte, Christian, witch, or fanatical devotee of Special Interest Lib. It doesn't really reflect on the cause itself. Ad hominem argument saves time, but it's still a fallacy.
17) No technique works if it isn't used.
If that sounds simplistic, look at some specifics: Telling friends about your diet won't make you thin. Buying a diet cookbook won't either. Even reading the recipes doesn't help. Knowing about Alcoholics Anonymous, looking up the phone number, or even jotting it down won't make you sober. Buying weights doesn't get you muscles. Signing a piece of paper doesn't cause a cease-fire, even if you make lots of copies and tell every anchorperson on Earth. Endlessly studying designs for spacecraft won't put anything in orbit.
18) Not responsible for advice not taken.
19) Think before you make the coward's choice. Old age is not for sissies.
20) Never let a waiter escape.
Niven’s Laws For Writers
1. Writers who write for other writers should write letters.
2. Never be embarrassed or ashamed about anything you choose to write. (Think of this before you send it to a market.)
3. Stories to end all stories on a given topic, don’t.
4. It is a sin to waste the reader’s time.
5. If you’ve nothing to say, say it any way you like. Stylistic innovations, contorted story lines or none, exotic or genderless pronouns, internal inconsistencies, the recipe for preparing your lover as a cannibal banquet: feel free. If what you have to say is important and/or difficult to follow, use the simplest language possible. If the reader doesn’t get it then, let it not be your fault.
6. Everybody talks first draft.