Gambling Act 2005. Gambling within the UK is regulated by the Gambling Act 2005 which since its inception has simplified the process for people who wish to gamble. There is no longer any red take as players who wish to gamble can simply sign up online or walk into a casino and start gambling.
In short, almost all forms of gambling are permitted for those of 18 years and over, and some forms of gambling (lotteries and some small prize amusement machines) are even permitted for those over 16.