CHICAGO (AP) - Boston-based DraftKings has filed a lawsuit against Illinois Attorney General Lisa Madigan a day after she declared daily fantasy sports betting illegal in the state.

CHICAGO (AP) Boston-based DraftKings has filed a lawsuit against Illinois Attorney General Lisa Madigan a day after she declared daily fantasy sports betting illegal in the state.

The lawsuit was filed Thursday in Cook County Circuit Court in Chicago.

Attorney Randy Mastro represents DraftKings, one of two industry leaders. He says the suit was filed so Illinois residents who have played daily fantasy sports for years will know they can continue to, in his words, "enjoy the fantasy sports games they love."

The lawsuit asks the court for an expedited opinion declaring that fantasy games do not constitute gambling within the meaning of Illinois law and nullifying Madigan's Wednesday opinion letter.

Madigan's office did not immediately respond to emailed requests for comment Thursday evening.