Circumstances Alter Cases American proverb
Other phrases in English have similar meanings, including drastic times that call for drastic measures and desperate times that call for desperate measures.
Certain conditions can change conventional actions or approaches.
A manager must be flexible and independent because circumstances alter cases.
Honestly, I don't want you to break the rule, but I think circumstances alter cases.
The etymology of this phrase has little information, apart from the fact that it was first recorded sometime in the 17th century.