I'm pretty sure it's a mix between 'hacker', the person cheating, and 'hacks, or hax', what they're using to cheat, "haxxor". Then they just started putting it on the end of everything. So instead of saying something 'rocks' it 'roxxors'. Pronounced rock-sors. It can be added to anything so long as it sounds right. eg. 'suxxor' in stead of sucks.
You could probably still use it if you don't play these games, it's easy to pick out the root words in them, but in doing so would probably label you as a 'gamer'.
'Teh' is common everywhere, not just online games.
>>n@t
You could modify it's use to work with any word so long as you can still pick out the root word. Therefore most words with the 'ck' or 'cks' sound will work. You can also just use the 'zor' ending on words, it doesn't even really matter how you spell it so long as it reads the same.