It is accepted that the age of legal gambling follows the age of maturity. In many countries this is generally accepted to be around the age of 18. However, it is not a norm and cannot be said for the entire world. Besides also for having an age of maturity, some countries even have various ages of legal consent, depending on the act of gambling that wish to do. For example, in Iceland you have to be 18 to legally gamble but can already at the age of 15 play the national lottery.
It should also be highlighted that gambling also is not just accepted everywhere we go. In some countries the act of gambling is completely illegal and a punishable offence that could potentially get you jail time, or worse. Some of these countries include Bahrain, Brunei Darussalam, Indonesia, Maldives, Pakistan, Saudi Arabia and Syria.
Land and Water Regulations
Cruise ship gambling is an entirely different scenario. The ships casino is regulated by the country in whose waters they are. Simple as what this might seem, some in some countries where it is illegal to gamble, like Israel, certain ships are permitted to run a casino when in those waters. Also, international waters become territorial waters when the ship sails within three to 12 miles from the coastline. The general rule is that the boat is considered to be an extension of the country under whose flag it sails. When sailing outside of the 12-mile coastline distance, you can expect the legal age of gambling to be 21. This is however not always a hard rule as some ships do allow for a legal age of 18.
On land the age of consent for gambling is generally between the ages of 18 and 21. But this in itself is confusing. As stated before, some countries have different ages for different gambling. These are not only the differences as pointed out in Iceland. For example, in New Zealand, you have to be 20 the be able to gamble in a casino but you can already bet on the horse races at the age of 18. While in Estonia you have to 21 to gamble in a casino, any other form of betting is allowed from the age of 16.
A Myriad of Rules and Regulations
The complications do not end there. In a country like China gambling is completely illegal yet they do have a national lottery that you can bet on from the age of 18. While in some countries like Afghanistan and Ethiopia, casinos and lottery are forbidden, but online gambling is legal at any age.
Portugal has complicated laws. It depends on each casino on what the legal age is that they accept. There are even casinos which allow tourists to gamble from 18, but the locals are only allowed to gamble from age of 25.
The USA, has three different legal gambling ages, depending on which state you are in. Because each state is governed individually.
It is therefore always best to, if you are younger that 21, to understand the gambling laws of the country you find yourself in, before just walking into a Casino.