知彼知己，百战不殆 (知彼知己，百戰不殆) zhī bǐ zhījǐ, bǎi zhàn bù dài

zhī bǐ zhījǐ, bǎi zhàn bù dài phrase knowing the enemy and yourself will get you unscathed through a hundred battles
Domain: Modern Chinese 现代汉语
Notes: From Sunzi's The Art of War (CC-CEDICT '知彼知己，百戰不殆'; Mathews 1931 '知彼知己，百戰不殆', p. 128)