On dispersive ground, therefore, fight not. On facile ground, halt not. On contentious ground, attack not. On open ground, do not try to block the enemy's way. On the ground of intersecting highways, join hands with your allies. On serious ground, gather in plunder. In difficult ground, keep steadily on the march. On hemmed-in ground, resort to stratagem. On desperate ground, fight.
Sun TzuAll warfare is based on deception. If your enemy is superior, evade him. If angry, irritate him. If equally matched, fight and if not: split and re-evaluate.
Sun Tzu