Chinese Proverbs 两虎相斗，必有一伤

liǎng hǔ xiāng dòu ,  bì yǒu yī shāng
两 虎 相 斗， 必 有 一 伤

  When two tigers fight, one is sure to lose.

解释 ( paraphrase )
两只老虎打架，必定有一只要受伤。
这条谚语告诉我们：双方争斗，总有一方要受到损害。劝诫人们不要盲目地互相争斗，盲目争斗的结果，只有害处，没有好处。

This proverb warns us that conflict between two sides results in one of them getting hurt. So it is best to avoid fighting as much as possible.
斗 (dòu)：争斗，打架。
                To fight, struggle.

同义词 ( synonym )
二虎相争，必有一伤
鹬蚌相争，渔翁得利

造句 ( example )
如果与谁都格格不入，不懂谦让，两虎相斗，必有一伤，这又何苦呢？与其受伤，还不如退一步，皆大欢喜。