(CBS) — Thousands of Illinois residents who play fantasy sports games on sites like DraftKings and FanDuel may be out of luck.

Illinois Attorney General Lisa Madigan released an opinion Wednesday afternoon stating the daily fantasy sports leagues constitute illegal gambling.

Fantasy sites such as FanDuel and DraftKings have argued that the contests are games of skill, not chance, and therefore do not constitute gambling. Madigan says state criminal code prohibits playing games of chance or skill for money.

The attorney general’s office says it may take some time before Illinois residents are banned from the sites. The office says players who use the sites are not breaking the law; it’s up to the companies to comply. It does not affect traditional, season-long fantasy games.

Democratic State Representative Michael Zalewski of Riverside has a bill in the state House Rules Committee now that he says would make it legal.

“It would adjust the concerns of the attorney general,” he said. “It would create an exception in our gambling laws to allow for daily fantasy sports to continue to operate.”

CBS 2’s Brad Edwards spoke with DraftKings player Bob Mason.

“It means my Sundays are going to be a little more boring now since I can’t play FanDuel so it’s back to just watching football,” Mason said.

He played, and it’s paid.

“It would make the games a lot more watchable,” Mason said. “Obviously the Bears haven’t been great, so it would be a big reason to actually have something to root for with the Bears.”

FanDuel issued a response to Madigan’s opinion saying, “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. 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.”

A spokesman for DraftKings released a statement saying, “We respectfully disagree with the Attorney General’s opinion and the reasoning behind it. We believe daily fantasy sports, which Illinois residents have been playing for years, are lawful under state law. We also believe, as the Attorney General has said, that this is a policy question for state legislators to address. That is why we look forward to working with lawmakers, like Representative Mike Zalewski and others, who wish to enact thoughtful and common-sense legislation that protects consumers’ rights to compete, while also adopting appropriate consumer protections.”