'Strict', 'severe', and 'harsh' are adjectives that can be used to describe laws. 'Tough' is also frequently used in speech or informal writing. 'Draconian' is a colourful word used to describe extremely harsh laws.

Native English speaker from the USA. The word hard doesn’t work here. I would use the term difficult to live by or difficult to live with. You could also use difficult to adhere to. Example: The 8:00 Nazi imposed curfew law was difficult to live by as many people were still trying to make their way home at that hour after working all day.

Thank you Mary!

We use the word strict in English.