To refrain from intercepting an enemy whose banners are in perfect order, to refrain from attacking an army drawn up in calm and confident array:--this is the art of studying circumstances.

故用兵之法，高陵勿向，背丘勿逆，
It is a military axiom not to advance uphill against the enemy, nor to oppose him when he comes downhill.

佯北勿从，锐卒勿攻，
Do not pursue an enemy who simulates flight; do not attack soldiers whose temper is keen.

饵兵勿食，归师勿遏，
Do not swallow bait offered by the enemy. Do not interfere with an army that is returning home.

围师遗阙，穷寇勿迫，
When you surround an army, leave an outlet free. Do not press a desperate foe too hard.

此用兵之法也。
Such is the art of warfare.


九变第八
VIII. Variation in Tactics

孙子曰：凡用兵之法，将受命于君，合军聚合。
Sun Tzu said: In war, the general receives his commands from the sovereign, collects his army and concentrates his forces

泛地无舍，衢地合交，绝地无留，围地则谋，死地则战，
When in difficult country, do not encamp. In country where high roads intersect, join hands with your allies. Do not linger in dangerously isolated positions. In hemmed-in situations, you must resort to stratagem. In desperate position, you must fight.

途有所不由，军有所不击，城有所不攻，地有所不争，君命有所不受。
There are roads which must not be followed, armies which must be not attacked, towns which must be besieged, positions which must not be contested, commands of the sovereign which must not be obeyed.

故将通于九变之利者，知用兵矣；
The general who thoroughly understands the advantages that accompany variation of tactics knows how to handle his troops.

将不通九变之利，虽知地形，不能得地之利矣；