SPRINGFIELD (AP) — Illinois’ attorney general says daily fantasy sports betting is illegal gambling under Illinois law.

Lisa Madigan issued an opinion Wednesday declaring that the argument over whether skill is required in betting on short-term fantasy-team contests is irrelevant. She points out that illegal gambling occurs when someone “plays a game of chance or skill for money.”

Daily fantasy sports differ from traditional fantasy contests because they are played over short periods — a week or even a day. Winners are decided on achievements of real players on virtual teams.

Riverside Democratic Rep. Mike Zalewski introduced legislation in October to legalize the contests. He said in a statement Wednesday that the opinion gives the matter “clarity” as he negotiates legislation to make daily fantasy betting “safe, fun play.”

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 law takes effect immediately. It does not affect traditional, season-long fantasy games.

FanDuel issued a response to Madigan’s opinion saying, “Chicago may be the best sports town in the country. They question why the Attorney General would tell her 13.5 million constituents they can’t play fantasy sports anymore as they know it – and they emphasize that her opinion bans all forms of fantasy sports played for.

They’re hoping legislature won’t approve the Zalewski measure.