I recently moved out of an apartment in which I lived from September 1, 2008-July 31, 2009. I never signed a lease, as my two roommates were basically renting the room to me without the permission of the landlord. I did not know that was the case until after I moved in and, though I disagreed with what they were doing, I needed a cheap place to stay. The landlord lives in California and never knew that I lived in the apartment.
My roommates each paid $600/month to the landlord, and I paid each roommate $200, so we each ended up paying $400/month. I told one roommate on the phone in June that I would be moving out August 1. I assumed she would realize that meant I wouldn't be paying rent in August, but she called me and left me a note the day before I moved out, requesting that I pay August rent. I refused and she is now threatening legal action but I don't believe she has a case. I considered paying just to avoid the aggravation, but would rather not if I don't have to. Just hoping for some other opinions. Thanks!

Editor's Response
I suppose the roommate might argue you did not give proper notice (fact specific issue). I guess if I were in your shoes I would just wait and see what she does. Hard to believe she will take you to court for $200, but if she does, even if you lose you still only owe $200.