The ordinary rule for use of military force is for the military command to receive the orders from the civilian authorities, then to gather and mass the troops, quartering them together. Nothing is harder than armed struggle.

The difficulty of armed struggle is to make long distances near and make problems into advantages.

Therefore you make their route a long one, luring them on in hopes of gain. When you set out after others and arrive before them, you know the strategy of making the distant near.

Therefore armed struggle is considered profitable, and armed struggle is considered dangerous.

To mobilize the whole army to struggle for advantage would take too long, yet to struggle for advantage with a stripped-down army results in a lack of equipment.

So if you travel light, not stopping day or night, doubling your usual pace, struggling for an advantage a hundred miles away, your military leaders will be captured. Strong soldiers will get there first, the weary later on -- as a rule, one in ten make it.

Struggling for an advantage fifty miles away will thwart the forward leadership, and as a rule only fifty percent of the soldiers make it.

Struggle for an advantage thirty miles away, and two out of three get there.

So an army perishes if it has no equipment, it perishes if it has no food, and it perishes if it has no money.

So if you do not know the plans of your competitors, you cannot make informed alliances.

Unless you know the mountains and forests, the defiles and impasses, and the lay of the marshes and swamps, you cannot maneuver with an armed force. unless you use local guides, you cannot get the advantage of the land.

So a military force is established by deception, mobilized by gain, and adapted by division and combination.

Therefore when it moves swiftly it is like the wind, when it goes slowly it is like a forest; it is rapacious as fire, immovable as mountains.

It is as hard to know as the dark; its movement is like pealing thunder.

To plunder a locality, divide up your troops. to expand your territory, divide the spoils.

Act after having made assessments. the one who first knows the measures of far and near wins -- this is the rule of armed struggle.

An ancient book of military order says, ``Words are not heard, so cymbals and drums are made. Owing to lack of visibility, banners and flags are made.'' Cymbals, drums, banners and flags are used to focus and unify people's ears and eyes. Once people are unified, the brave cannot proceed alone, the timid cannot retreat alone -- this is the rule for employing a group.

So in night battles, you use many fires and drums, in daytime battles, you use many banners and flags, so as to manipulate people's ears and eyes.

So you should take away the energy of their armies, and take away the heart of their generals.

So morning energy is keen, midday energy slumps, evening energy recedes -- therefore those skilled in use of arms avoid the keen energy and strike the slumping and receding. These are those who master energy.