In the state of Illinois, gambling is generally a crime unless it is done in a way that has been legalized, such as the Illinois Lottery or at a licensed casino. The crime of gambling is defined by 720 ILCS 5/28-1 follows:
A person commits gambling when he or she:
(1) knowingly plays a game of chance or skill for money or other thing of value, unless excepted in subsection (b) of this Section;
(2) knowingly makes a wager upon the result of any game, contest, or any political nomination, appointment or election;
(3) knowingly operates, keeps, owns, uses, purchases, exhibits, rents, sells, bargains for the sale or lease of, manufactures or distributes any gambling device;
(4) contracts to have or give himself or herself or another the option to buy or sell, or contracts to buy or sell, at a future time, any grain or other commodity whatsoever, or any stock or security of any company, where it is at the time of making such contract intended by both parties thereto that the contract to buy or sell, or the option, whenever exercised, or the contract resulting therefrom, shall be settled, not by the receipt or delivery of such property, but by the payment only of differences in prices thereof; however, the issuance, purchase, sale, exercise, endorsement or guarantee, by or through a person registered with the Secretary of State pursuant to Section 8 of the Illinois Securities Law of 1953, or by or through a person exempt from such registration under said Section 8, of a put, call, or other option to buy or sell securities which have been registered with the Secretary of State or which are exempt from such registration under Section 3 of the Illinois Securities Law of 1953 is not gambling within the meaning of this paragraph (4);
(5) knowingly owns or possesses any book, instrument or apparatus by means of which bets or wagers have been, or are, recorded or registered, or knowingly possesses any money which he has received in the course of a bet or wager;
(6) knowingly sells pools upon the result of any game or contest of skill or chance, political nomination, appointment or election;
(7) knowingly sets up or promotes any lottery or sells, offers to sell or transfers any ticket or share for any lottery;
(8) knowingly sets up or promotes any policy game or sells, offers to sell or knowingly possesses or transfers any policy ticket, slip, record, document or other similar device;
(9) knowingly drafts, prints or publishes any lottery ticket or share, or any policy ticket, slip, record, document or similar device, except for such activity related to lotteries, bingo games and raffles authorized by and conducted in accordance with the laws of Illinois or any other state or foreign government;
(10) knowingly advertises any lottery or policy game, except for such activity related to lotteries, bingo games and raffles authorized by and conducted in accordance with the laws of Illinois or any other state;
(11) knowingly transmits information as to wagers, betting odds, or changes in betting odds by telephone, telegraph, radio, semaphore or similar means; or knowingly installs or maintains equipment for the transmission or receipt of such information; except that nothing in this subdivision (11) prohibits transmission or receipt of such information for use in news reporting of sporting events or contests; or
(12) knowingly establishes, maintains, or operates an Internet site that permits a person to play a game of chance or skill for money or other thing of value by means of the Internet or to make a wager upon the result of any game, contest, political nomination, appointment, or election by means of the Internet. This item (12) does not apply to activities referenced in items (6) and (6.1) of subsection (b) of this Section.
Illegal gambling in Illinois is a Class A misdemeanor, which means the maximum penalty is 1 year in the county jail. However, a second or subsequent conviction under subsections (3) through (12),that are shown above is a Class 4 felony, which can result in a sentence of 1-3 years in the Illinois Department of Corrections (prison).