The Art of War by Sun Tzu: if not the first treatise ever written on war as a formal practice, it is certainly the most famous, both in the hoary Orient and around the world. While the book was written more than 2000 years ago, and is, in fact, surprisingly short, it is still highly relevant to masculine men today, even if you aren’t literally commanding a contingent of men into battle. Many corporations require their executives to read the book, because its advice works for labor management, or even managing your own life.

And while of course morality has changed just a bit from 500 BC to now (the chapter on how to use fire as a weapon may not be the most relevant to your life, and tactics such as fake surrenders are forbidden by the Geneva convention), here are some of the tenets Sun Tzu espouses that are immediately relevant to your or anybody else’s life:

1) Preparation is the key

To quote the man himself: “War is a matter of vital importance to the state; a matter of life and death, the road either to survival or ruin. Hence, it is imperative that it be studied thoroughly.”

These are the words that open the book, and the idea of war as being something you can prepare and study for is one that permeates throughout the book. As your grandma probably told you at some point, an ounce of prevention is worth a pound of cure. In war specifically, there are five main factors to be concerned with and prepare for:

1) The moral law (the people’s relationship to the commander ie: you the reader, whether or not they will follow his orders)

2) Heaven (weather conditions, night and day, etc.)

3) Earth (the terrain, distances, etc.)

4) The commander’s abilities

5) Methods and discipline of the army (which includes supplies and budgeting and logistics)

Those of you unfamiliar with this may protest that these seem to be “common sense” aphorisms—and yes they are. But again, remember that this book was written 2500 years ago. Common sense may not have been so common back then. And in fact, the mere notion that Sun Tzu completely eschews any supernatural effects to warfare was revolutionary back then (he explicitly instructs the reader to “prohibit soothsaying and omen reading”).

You cannot force the enemy to fight or make a mistake, all you can do is take precautions so that you don’t lose.

The book clarifies that there are three ways a ruler (note: RULER, not GENERAL) can fuck up his army:

1) Give them orders they can’t follow

2) being ignorant of the conditions in the field, and

3) Employing officers without discrimination—ie, not picking the best man for the job.

But with all that being said…

2) Be prepared to throw out your plans if need be.

While it is imperative to know about those five things and prepare for them, don’t be afraid to change things up. If there is some other unorthodox thing that will give you the advantage, take it! Modify your plans based on the circumstances. In general cleverness is not associated with long waits, but of course stupid haste is no good either.

Or to quote Sun Tzu again: “There are not more than five musical notes, yet the combinations of those five give rise to thousands of melodies”. Ignoring the fact that the ancient Chinese man is showing his provincialism by only knowing about the pentatonic scale, the point still stands.

In battle you can basically chosose two methods of attack—direct and indirect—or defense, but these can combine for an endless variety of moves.

3) To win without fighting

Again, it depends on circumstances, but go out of your way to make yourself look stronger or weaker, depending on what the needs of your plans are. “The acme of skill in warfare is to win without fighting, to win through deception”. Intimidation can also work, to make it clear to the enemy “If you fight I will be merciless but if you surrender I’ll let you go”. To show the efficacy of this tenet,  1700 years later, another fellow in the region would use this technique masterfully.

4) Hurt the enemy in violent and non-violent ways

In addition to fighting him, work the logistic/strategic side. Take supplies from him in addition to your own logistics. Bait him into attacking and making sloppy mistakes (whether it be by feigning disorder and weakness or insulting him to rouse him to anger). Remember that when he attacks one place or reinforces one place, he is making another place weaker.

5) Pay attention to what the enemy does

Use spies and find out his plans whenever possible. Observe him and surmise what his situation is like based on how he acts—Sun Tzu cites an example of seeing the enemy slaughtering their horses and burning their ships for firewood, and quite clearly knowing they were desperate. While most situations will not be so obvious, you can figure out much of the enemy’s situation from “open sources”.

Indeed, pay attention to your surroundings in general—animals in the surrounding area (or a total lack of them) are a great marker of enemy activity, to cite one example.

6) Be like water

Bruce Lee said this for a reason— water in its natural course runs away from high places and trickles down. Similarly, attack the weak spots and retreat from the strong spots. Water shapes its course  based on the ground it flows over. Similarly you have to change your tactics based on the circumstances.

7) Don’t be afraid to tell your supervisor to fuck off

Probably the hardest one in the book. As the famous quote says “if fighting is sure to result in victory, then you must fight”. In context, this is saying “even if your monarch is telling you to not fight, if you know it’ll be beneficial, then ignore him”.

8) Mercy to friends and enemies

Much of the book has Sun Tzu discussing matters of discipline—he advocates a “tough but fair” demeanor in which you demand much and discipline your soldiers harshly to get them to perform, but praise and reward them when they do good.

You should allow the enemies to retreat and surrender if possible, both to show your magnanimity and also to prevent them from making a desperate last stand that, even if you win, will still do significant damage.

9) The five flaws of a bad general

Recklessness, cowardice, quick temper, overly fixated on honor and shame (Rather than being fixated on actually winning the fight), and being overly cautious (not necessarily the same as cowardice)

When an army loses, the cause is more likely than not one of those.

And finally…

10) Terrain

While this is probably not as relevant for the businessman, being aware of your surroundings, and using them to your advantage, is still something to keep in mind.

These tenets seem relatively simple, but of course implementing them is a lot trickier than reading about them. But now is as good a day as any to start practicing.