MacBook Pro will not close all the way

Thank you, MoonJ. for your prompt response. After I posted the above query, I contacted Apple Support and, after finding out whether I had cleaned my MacBook in accordance with the Apple-recommended instructions, (I had), and ascertaining that nothing was physically impeding the top from closing smoothly as it always had, Sara, the young lady I spoke with, suggested that I have it visually inspected by a technician at a nearby Apple-approved computer center that she gave me the address of. I have an appointment there on Tuesday afternoon.

I am concerned because, in speaking with an acquaintance who is a long-time Apple aficionado, I mentioned that I had been playing a computer game gifted to me (my birthday was earlier this month) from Macgames.com, which I researched briefly and found out they are reputable, and they even said, by scanning my Mac, ( I guess, I never told them anything) that my Mac met the requirements for the game, so I dowloaded and played it. After a while, I noticed the fans had come on (I could hear them) which almost never happens, and I noticed that my computer was very hot. I immediately shut it down and left it in the open position to cool for an hour or so. When it had cooled, I closed the top, only to find it would not close completely. My friend thinks the battery overheated and swelled, causing the top to not be able to close smoothly anymore. He said it is a common and recurring problem with Macs. He said he doesn't think it is as easily solved as opening it up and swapping out the battery for a new one. So, I am afraid of facing an expensive fix or having to accept having a slightly damaged computer. It still works fine in all other ways.

If this is a known, long-time problem, though, that Apple is well acquainted with, I don't understand why they haven't either found a fix for it, or at least why they do not warn customers that this could happen. It sure would have saved me a lot of (potential) grief. Anyway, I guess I'll find out what is going on Tuesday.

Thank you once again for your response.

Best Regards.