Others have given valuable input but no one has (unless I missed it) questioned the amount of alcohol your boyfriend consumes.

You state that he likes to play games and get drunk. Anyone familiar with alcoholism and addiction knows that isolation is often indicative of a substance problem. Additionally, substance abuse problems often resemble other disorders and frequently interfere with diagnoses. You may wish to try the CAGE test on your boyfriend:

Does/has he tried to Cut-down his drinking/using?
Does he get Angry when anyone tries to talk to him about his drinking?
Does/has he ever felt Guilty about his drinking or what he did while drinking?
Does/has he ever had an Eye-opener in the morning?

An affirmative answer to any of those questions indicates there may be a problem with alcohol or drugs and warrants further investigation.

Good luck!