Is 'When in Rome, do as the Romans do' a legal defence?

As a general rule, that is the case. However, because people were taking advantage of the situation to commit sexual offences against children, the Sexual Offences Act 2003 made it an offence for people from the UK to behave in a way permissible under the local legislation. http://www.fco.gov.uk/en/travel-and-living-abroad/...

There is also constant debate about whether or not people accompanying friends or relatives to countries allowing suicide should be prosecuted for doing so. http://www.guardian.co.uk/society/2009/sep/23/assi... The fact that it is allowed by the law of the countries concerned does not affect the (potential) criminality of those travelling there for this purpose.

Well, that doesn't mean using drugs legally in Amsterdam and failing a drug test back home in New York and getting fired won't happen. It certainly will happen if you are in a safety-sensitive job and your employer has any sense at all.

On the other hand when you are under the jurisdiction of a foreign country, as in being a legal visitor, then their laws or lack of laws apply to you. However, to be safe, it is best to obey the laws of both countries unless they actively conflict. In that case, obey the laws of the country which has jurisdiction.

And no, it isn't a defense, nor is it a defense when you are tagged for violating a law that a bunch of other people, nit arrested, are also violating.

Only in a few instances can you not "When in Rome, do as the Romans do".

Usually it involves going to other countries to have sex with under-aged males/females.

If you are referring to going to another country and taking legal drugs in that country (which may not be legal in your own country), it is probably not illegal, but you better have it completely out of your system when you return.

In general you follow the laws of where you are and you won't get in trouble when you go home. Doesn't matter what the law is back home because you aren't in the jurisdiction of your home nation.

The phrase was never intended to be legal advice. Merely a suggestion that tourists should adopt the local way of life.

No you can't get in trouble in the UK or US for smoking hash in Amsterdam.

Was I close?lol