Saudi Arabia is a conservative country where Islamic laws are observed. Though locals are generally tolerant and will not take offence if rules are not strictly observed, it is a good idea to follow social etiquette during your trip.
In terms of law, the consumption of alcohol is banned and public decency laws must be respected. Both men and women should dress modestly. Men should wear long trousers, not shorts, and long-sleeved shirts. Women should carry a headscarf for occasions where covering of the hair is appropriate.
Be aware that prayers are observed five times per day and shops and restaurants may briefly close during these times.