Many people gamble in the hope of winning money without considering the risks involved. By using probability theory it is possible to estimate the chance of certain events. For instance, one can estimate the probability that a poker player is dealt a full house or that a gamer wins a bet in a roulette game. In fact, the mathematics of gaming is a collection of probability applications encountered in games of chance. The reason why casinos, lotteries and gaming companies make profits is that probability is in their favour.

Suppose that a gambler A offers €18 to another gambler B if the total score of two fair dice is 10 and B pays €12 to A if the total score is 7. Although the game seems advantageous to gambler B, probability theory shows that the game favours gambler A since the probability of getting a total score of 7 (6/36) is double that of getting a total score of 10 (3/36). To establish whether a game is fair one must calculate the ex­pected gain for each gambler, which is the amount the gambler stands to win multiplied by the probability of winning. The game is in A’s favour since his expected gain (€12 x 6/36=€2) is larger than his expected loss (€18 x 3/36=€1.5)

There are several misconceptions when gamers select numbers for a lottery. Choosing the same numbers each time does not guarantee that they will eventually win. In addition, picking a number close to a winning number does not imply that the gamer was close to winning.

Undoubtedly gaming is a popular source of entertainment for many people.  By understanding the probabilities behind gaming one realizes that the probability of winning a game is always against the gamer and in favour of the house (casino or lottery).  The belief that persistence leads to success is never true in gaming. Actually, persistence in gambling leads to bankruptcy.