Your parents need to really and fully understand the seriousness of the situation.

Maybe I'm reading too much into your OP, but from what you wrote it could be that at least your mother is feeling some guilt because of his chronic disease and thus acting wrongly despite knowing better.

I'm reading this into your words as your story reminds me of this brother of a close friend of mine who somehow managed - as strange as it sounds - to make his mother feel guilty about his acquired type 1 diabetes when he was a child and teenager. Today he's an adult in his early 30s without a job or any perspective (I know the family since my childhoood). Throughout the past 15 years or so he was not willing to make even the slightest effort to get a job or change the situation, he just pretended to do so. Unlike your brother he was never addicted to anything but he lied to his family every single day (the most important example which really shocked me when I heard of it: He left the family for more than 5 years to study law. When he returned he pretended to apply for jobs - over the years he had became an expert liar instead of an expert lawyer - and it took another year until the family realized that he'd actually never finished his studies. He probably never even really started. He was about 25 years at that time and until today he never had a job in his life). He has one younger brother and two younger sisters, and then there's this youngest brother who died in a car accident at the age of 18 (which imo is a key element of this particular family story). His siblings gave up fighting against his egoism and against their mother's will a few years ago. Some day they just had to realize that their mother will always let him do whatever he wants, i.e. nothing, and that their father is too good-natured - and imo unfortunately also much too weak - to change the situation. The parents never really understood or never wanted to realize that they needed outside help. I'm afraid the guy will live jobless and with his parents until they die.

Sorry for the long story. It wasn't by any means meant to discourage you - in fact I think it's great that, unlike your parents, you realized the seriousness of the situation early enough - but, in short and in my opinion based on my experience with this family:

As long as your parents are not in the same boat as you, I don't think you have a chance to change anything.

Its a cycle of escapism.

Playing video games to some is a way to escape the pressures of life. Some people play a lot of video games because they really just can't face responsibilities or even because they are ashamed of how they see themselves in the real world.

Playing a lot of games thus strengthens the thought that your not good enough in the real, so you play even more to forget. Vicious cycle. I know cause I had a friend back in the day go through it.

The only solution is a cut off cold turkey. Im talking sell all consoles, monitor the PC for any game data and erase it. It is gonna be a hard time but you have to convince the person they hit rock bottom and there is no other way. Eventually my friend re-enroled into school, moved up in his job, and now has a steady girlfriend. When you spend hours on playing video games to instead better yourself in real life, you'd be impressed.

I really hope this helps.

u know i have been through this period from year 8 till 11 when i moved to my new shitty school. U Can't argue with him cause he doesn't care anymore about anything but playing his games. Year 12 was a year of improvement and the 3 months i am having at university right now is the best time i have ever felt in my life. U have to help him cause one day he will regret it and ask why you and his mum didn't do anything. You have to take the videogames away from him, lock him in his room and give him an open invite to go wherever he wants as long as it isn't highly related to videogames, try and introduce him to a chick you trust who will be kind to him but you have to tell him how to talk to chicks before you do that just the basics.
They will have a good time and will make him realise that there is more to life than just video games. Some people don't know what they want until they try it.

Force him to go to skool. Call the social authorities or the police if needed.

I agree with slime beast. I think you should try with your parents a few more times to get them more involved with your brother's situation. If they continue to be uninvolved contact social services, tell them your parents are allowing your brother to not go to school and then they will become involved. If you don't feel comfortable going directly to social services you could tell a teacher or councilor at your school about the situation and they will probably contact social services.

I can see this possibility being stressful as it could be seen as going against your family. But if your brother is your primary concern, then this is the best way to ensure he gets the help he needs.

If I stole 10 dollars from parents my parents would turn my world upside down.

He stole $800 dollars.....

I would be in juenile detention if I was still that age and had done that.

Also if your smart you don't need to spend a cent on TF2, I've got all the hats and mics I want and I don't spend a dime, just need to trade smartly and conserve metal.  (Though I did buy the taunts ;p)

The damage is already done. Now just try your best to keep the drugs away from your potential junkie-brother.

What has been needed to be said has been said there isn't much point in repeating it, but I will add these three incredible videos from the Guys at Extra Credits--

100% agree with this. Resorting to violence solves nothing in this case. Honestly, it rarely solves problems in majority of cases, especially in child raising. It will only cause the kid to resent his parents, who coincedentally are the same people who are responsible for the child falling into these bad habits.

The answer to this is simple. Take the games away.

If the kid can stay home all day and play video games then he sure as hell can go to school and learn. If he can stay up until 11:30PM to play Halo then he sure as hell can stay up late and study.

I don't see thie chronic fatigue hindering him in the activity he feels like doing so the parents need to take some action, be responsible and get this kid off his ass and back in school.

You don't get symphathy for feeling tired and the parents sure as hell don't get any symphathy for giving into this kind of behaviour. This kid has been enabled by the parents to act like this and because of that he has no drive what so ever to return to school.

This is a problem the parents need to solve and if they can't then shame on them because they are allowing this kid to destroy his future.

Tell him he has a problem, and his life is gonna be shit if he doesn't fix it.

Tell your parents this aswell (maybe show them this post and make them read it) and get them to back you up on the following: Take the wires that connect the console to the TV or power supply while he is asleep or out and tell him he will get them back after he goes to school, every time he doesn't have a legitimate reason to not go into school, take the wires. I say the wires because you can easily hide them, and he will need them to play. He could find the consoles or controllers if you took that away. This includes the wires to your desktop or if it's a laptop, that may be tricky but you could try hiding that if you can't find another way.

It's basically hiding the heroin from the junkie, and it's not like he makes any money, so he can't go out and buy the heroin (games) himself. Take off your details from the xbl/psn/steam etc. and don't let him near your credit/debit cards, tell your parents to do the same.