unspoken rule 不言而喻的规矩，潜规则

　　This game is following some unspoken rules.

　　这个比赛有一些潜规则。

　　I'm new here. Could you tell me about the unspoken rules in this company.

　　我是新来的，能不能跟我说说这个公司的潜规则？

　　疯狂练习吧！