What's the difference between unlawful and illegal?
Dear Straight Dope:
What is the difference between "illegal" and "unlawful"? (Please, no old jokes about sick birds.) I can understand why legislators would want fancy words in the official law books, but what is the reason to put "unlawful" on street signs and other places where simple words would work better?
While I guess it would depend on what the sign was warning you against, the short answer is that they are two different things. Illegal means "against or not authorized by law." Unlawful means "contrary to, prohibited, or unauthorized by law...while necessarily not implying the element of criminality, it is broad enough to include it." (Black's Law Dictionary) So, for example, you could unlawfully stay in your apartment after your lease is up (unlawful detainer) but that's not a crime against the state, it's a civil wrong (tort) against your landlord. If the landlord then took you to court and had you properly evicted, and you then returned to the premises, you might then be guilty of the crime of trespassing. Trespassing is illegal. See how easy?