There aren’t any European countries where gambling is illegal in full. Generally, countries in Europe allow for some sort of gambling (online and/or offline). As a result, there is no easy way to sum up the gambling laws of Europe, as they differ a lot from one country to another. For EU states, the laws just have to comply with the Treaty on the Functioning of the European Union (TFEU). Instead, each member country of the EU (and every country in Europe) is free to set its own gambling laws. There are no official EU gambling laws or regulators operated by the European Union. What is important to note, however, is that while these terms are often used, there is no such thing as an official “EU casino”.
Often these casinos accept Euros as a currency and might have an English website or multilingual for different languages. The terms “European casinos” might also be used. “EU casinos” is generally used to describe land-based or online casinos based in and accepting players from the EU/Europe.