1. One-Number Lottery Games are games where the player selects just one number with multiple digits. Although the number of digits can theoretically be anything, all US lottery one-number games are invariably either 3-digit games or 4-digit games. 3-digit lottery games are played by simply selecting a 3-digit number from 000 to 999. These games are known by several names in different states; some common names are Cash 3, Pick 3, Play 3 and Daily 3. Similarly, 4-digit Lottery Games are played by selecting a 4-digit number from 0000 to 9999 and they are identified by names such as Cash 4, Pick 4, and Play 4.

   In both 3- and 4-digit games the player can choose to play the selected number as Straight (Exact Match) or as Box (Any Order Match). Playing a number as Straight means betting that the number will come in the exact order as played; player will win only if the winning number is exactly the same as his/her number. On the other hand, a Box play is when the player selects to bet on the three (or four) digits without regard to their order; player wins as long as the winning number contains all the three (or four) digits that he/she has selected in any order. Obviously, a winning Straight pays much more than a Box for the same amount wagered. The player may also choose to play his/her number as Straight/Box which, in many states, means that half of the money wagered is for Straight, and the other half for Box. Furthermore, several states offer additional play types known as Combo, Front Pair, Back Pair, and Split Pair. A more detailed description of 3-digit and 4-digit play types can be found at US-Lotteries.com or at the official state lottery web sites.

2. Multi-Number Lottery Games with one set of numbers are played by selecting 4, 5, or 6 numbers from 1 to a certain maximum specified by the game. The order in which the numbers are selected does not matter; the only exception to this rule is the Mix & Match game played in Pennsylvania.

   These games are usually denoted by the abbreviation n/N, which is interpreted as "the player selects n numbers from 1 to N". Depending on the value of n, these games may be 4-number games, 5-number games, or 6-number games. Most "Lotto" games in the United States are 6-number games. A common example is the Classic Lotto, a 6-number game denoted by 6/49, where the player selects 6 numbers from 1 to 49. There are also several 5-number games known by different names such as Fantasy 5, Cash 5, Pick 5 that fall into this category.

   In most multi-number games, prizes are awarded for 3 or more correct numbers. If a player gets all the n numbers correct, he/she is said to have hit the Jackpot, resulting in a lucrative prize money. If there are more than one Jackpot winners, the Jackpot money is divided equally among the winners (called pari-mutuel).

   In some states, in addition to the n numbers, an additional number is drawn from the same set of numbers and is known as a Bonus Ball. The Bonus Ball is usually used to increase the amount of lower prizes. As far as number selection on the part of the player is concerned, the Bonus Ball has no effect whatsoever. Therefore, these games belong to this very category.

3. Multi-Number Lottery Games with two sets of numbers are played by selecting the numbers from two sets. Four or five numbers are selected in any order from the first set, and one number is selected from the second set.

   These Multi-Number games are denoted by the abbreviation n/N + m/M, which means that the player has to select n numbers from 1 to N, from the first set and m more numbers from 1 to M from the second set. Except the multi-state lottery game called 2 By 2, where the player has to select two numbers from both sets, all US lottery games that fall into this category are played by selecting only one number from the second set (i.e., m = 1). Consequently, these games can be denoted by the abbreviation n/N + 1/M. The number selected from the second set is usually called the Mega Ball or the Extra Ball. Two very popular multi-number games with two sets of numbers are the Powerball, denoted by 5/55 + 1/42, and the Mega Millions, denoted by 5/56 + 1/46.

   Note the difference between an Mega (Extra) Ball and a Bonus Ball. A Mega Ball has to be selected by the player. A Bonus Ball is not. It is only drawn. Recall that games with a Bonus ball fall into the previous category.

4. Keno games are basically multi-number games like category 2, where the player selects 20 numbers from 1 to 80 or 82. The difference from category 2 games is that the player does not have to predict correctly all the 20 selected numbers in order to win the top prize. Usually 10 correct entitles him/her to the top prize. If it is a spot game, the player can even pre-indicate how many correct to expect.

As indicated at the beginning of this article, the foregoing classification is valid only to 'drawn' games, and not to the other widely played games known as Scratch-offs or Scratchers. Still, there are two 'drawn' games that do not fall into the above categories. They are the Daily Derby, a horse racing game played in California, and the Kicker game, played in Ohio, which is actually a primitive game where ready-made numbers are sold to the players.

The author's website us-lotteries.com, which is updated several times a day, presents a vast amount of information on all United States drawn lottery games. You'll find basic games fundamentals, past winning numbers analysis, RSS feeds of latest numbers, odds calculators, lottery wheels, combinations generators, and much more