Your roommate is guilty of fraud if he cashed the check. You can have him expelled for that, as well as arrested. I would suggest doing both.

charge him for it. but YDI for not hiding it where he wouldnt find it.

Definitely call the police. You have a "written" confession from him. He had no right to take your money, your name was on the check not his. And next time, hide your money. I know it's hard to do in a dorm but either cash it right away or find somewhere to hide it.

reply saying "No you borrowed MY money at 15%/day interest and gambled it away. pay up soon."

wtf people? There's no way this is real. The guy can't cash a check if its not his name on the damn thing. No one can use that check but to the person its signed to. Meaning this FML is fake.

That is theft, and assuming your roomie cashed the check, it's fraud as well. It's possibly identity theft, too. Your roommate could end up in jail for a long time. Tell him if he doesn't give your money back that you'll call the cops. And don't delete that text just in case. In the future, keep your money where it's safe or do a direct deposit.

Your roommate is a fuckface

Also, the guy could have went to an ATM and deposited it into his own account, assuming he has one.

oh dont worry OP if he went to an atm and deposited the check he gonna all the suddent notice the amount of the check missing from his account when the bank processes the cheque's and the bank will probaly call you to check if you let him deposit the cheque in his account and then you just tell them no and that he stole it simple as that

FAKE. He wouldn't be able to cash your check, because he would need to show ID, and obviously, he isn't you. The only way to cash it would be for him to put it into YOUR bank account, which he wouldn't be able to withdraw from.