OK give us the context! He eats no fish = he doesn't eat fish He plays the game = he sticks to the rules

I agree with Sarah, this so called idiom is not used by English native speakers.

Here's what I found: http://eng.hi138.com/?i50959# Honestly, you'll never hear an English speaker using this "idiom". I guess it's a translation from a Chinese idiom? I don't know, I didn't read the entire website. Like 一 said, there's some sort of history tied to the words, but really, it's just kind of pointless. Why learn idioms that no one uses / will understand? :) Main point I want to stress: You won't hear this from English speakers and most people won't know what it means.

I would suggest you to Google it yourself. And then, funny you'll find the answers are all from some China's English-learning websites. Somewhat an idiom. Somewhat a British historical story. What it is about is not important for you to know. To myself it is just embarrassingly interesting to see, as I found before, Chinese know more English idioms than English-speaking people. : /

“eat no fish”是同意政府、机构、上级、的某种政策。plays the game是只按照规则办事。eat no fish 的出处是伊丽莎白一世宗教改革，改革中的一条是在周五不吃鱼，于是她的支持者就把“eat no fish”喊了出来。这个在英国文化里比较有人使用，美国人....应该不会太了解。