一物降一物

yīwùxiángyīwù
  1. lit. one object bests another object
  2. every item has a weakness (idiom)
  3. there is a rock to every scissor, a scissor to every paper, and a paper to every rock

CEDICT

there is always one thing to conquer another; everything has its vanquisher

Wiktionary

比喻任何事物必有另一事物可以降服它。《西游记．第五一回》：「常言道：『一物降一物』哩。你好违了旨意？但凭高见，选用天将，勿得迟疑误事。」《儿女英雄传．第二一回》：「你看好个摆大架子的姑娘，好一班陪小心的强盗，这大概就叫作『财压奴婢，艺压当行』，又叫做『一物降一物』了。」也作「一物剋一物」、「一物一制」。

重編國語辭典

Entry Composition

1 一物 yīwù
  1. (literary) one thing; one object
  2. one thing; one object
2 降 xiáng
  1. to surrender; to capitulate
  2. to subdue; to conquer; to tame
3 一物 yīwù
  1. (literary) one thing; one object
  2. one thing; one object