SPRINGFIELD, Ill. -- Daily fantasy sports betting is illegal gambling under Illinois law, Attorney General Lisa Madigan said Wednesday.

Madigan's opinion, sought by two Democratic legislators, points out that the debate over whether the popular contests involve skill or luck is irrelevant. Illinois outlaws both.

The law "clearly declares that all games of chance or skill, when played for money, are illegal gambling in Illinois," Madigan, a Democrat, wrote.

Madigan's decree follows decisions in New York and Nevada to ban the online sites for the same reason. Democratic Rep. Mike Zalewski of Riverside, who is pushing legislation to legalize and regulate the contests, said that while he disagrees that the pastime involves gambling, the ruling provides "more clarity."

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Zalewski said in a statement that he's aiming for regulations "to allow Illinoisans to continue to play these contests and provide the necessary strong consumer protections for safe, fun play."

FanDuel, one of the two major players in the daily fantasy sports industry, issued a statement to CBS Chicago in response to Madigan's opinion.

"Chicago may be the best sports town in the country... So why the Attorney General would tell her 13.5 million constituents they can't play fantasy sports anymore as they know it -- and make no mistake, her opinion bans all forms of fantasy sports played for money -- is beyond us," the statement said. "Hopefully the legislature will give back to the people of Illinois the games they love. A sports town like Chicago and a sports loving state like Illinois deserves nothing less."

Boston-based DraftKings said in October that Zalewski's approach, requiring players to be 18 and allowing sites to review players for child support or tax debts, was "reasonable and measured."

Daily fantasy sports differ from the traditional model in that contests are organized around short periods -- a week, or a day -- instead of a season. Players compete for a predetermined prize by assembling virtual teams of real pro or college athletes; winners are determined based on the statistics those athletes compile.

Madigan pointed out that while state law allows prizes or compensation for "actual contestants," that doesn't include fantasy gamblers.

"Persons whose wagers depend upon how particular, selected athletes perform in actual sporting events stand in no different stead than persons who wager on the outcome of any sporting event in which they are not participants," Madigan wrote.

Nevada regulators declared the bets illegal gambling and ordered the sites out of the state unless they acquire gambling licenses; New York's attorney general ordered DraftKings and FanDuel to stop operating, but the companies won a temporary reprieve allowing them to continue through January. Madigan's opinion made no such orders.

Democratic Reps. Scott Drury of Highwood and Elgie Sims of Chicago sought the opinion. Drury said not only did taxpayers need to know whether the contests were legal, lawmakers needed to know what they are attempting to regulate.

"To me, it didn't make sense to consider legislation when we didn't know what the current status of daily fantasy sports is in Illinois," Drury said. "Now that we know, according to the attorney general, that it's illegal, we can make a serious attempt to address the issue."

Drury is not a fan of Zalewski's proposal, saying the minimum age of 18 is too young and that rules are too loose on winners who owe child support or tax money. Zalewski said he aligned parameters with current gambling regulations on riverboat casinos and horse racing.

"I disagree with those sentiments, but we have whole spring ahead of us to work on a bill that addresses concerns like that," Zalewski said.