The Once and Future King Book 2, Chapter 12
The battle is fought like two battles: the masters (kings, knights, etc.) who don't seriously want to hurt each other, and the slaves, who fight mostly for their masters' entertainment. Arthur, on the other hand, wants his men to fight the enemy's leaders: "They were to press the war home to its real lords-until they themselves were ready to refrain from warfare, being confronted with its reality." Book 2, Chapter 12, pg. 308 Arthur does not fight by the rules: he attacks at night, and he only attacks the leaders of the opposition, leaving the foot soldiers alone. King Lot, who is used to the old, chivalric way of fighting, is confused and cannot respond well to these attacks. He and his comrades surrender.