The legal drinking age like so many laws varies greatly around the world ranging from some countries that have no legal minimum age at all to those who forbid alcohol altogether, albeit often unsuccessfully.
Complicating matters further many countries have various loopholes and exceptions to the laws making them all but incomprehensible to anyone not from the immediate area. Some countries for example make alcohol illegal to buy or sell below a certain age but not to consume. Others have different sets of laws depending on the strength of the alcohol, or concerning where the alcohol can be sold.
In the United States the legal drinking age is currently 21 although each state has its own specific laws concerning how alcohol can be sold. In some areas for example, beer and spirits are sold in separate store other than in bars and cannot be bought on Sundays.
There are also dry counties in the Unites States where alcohol is completely or partially illegal to buy or consume although often is still legal to produce. Famously Jack Daniels whisky originates from Moor county Tennessee, a dry state where it cannot be legally consumed.
The U.S also has numerous rarely enforced and often bizarre laws concerning alcohol covering such pressing issues as feeding alcohol to a moose, or being able to buy alcohol in certain sized containers.
Britain by contrast has relatively simple drinking laws with a legal age of 18 although there are still odd exceptions. In England for example the minimum legal age to consume alcohol is 5 in the home and 16 if drunk with a meal in a pub.
France was previously famously known to allow children to drink wine with meals but while this practise still goes on in the home, the laws regarding drinking in restaurants or bars have recently been altered. Intoxication of minors is now illegal and the minimum legal age for drinking in restaurants and bars has been raised from 16 to 18.
Much of europe tends to emphasize laws regarding the sale rather than consumption of alcohol, often essentially leaving the consumption of alcohol up to parents rather than the state. Many also differentiate between weaker and stronger types of alcohol. In Holland, Austria, Germany and several other countries the legal purchasing age for beer is 16 but 18 for spirits over a certain strength.
Of course in many Muslim countries such as Saudi Arabia, Pakistan, Iran and the like, alcohol is illegal to distribute, produce or consume. That being said however many tourists report that alcohol is still widely available, even if not used by the locals.