I have played fan-made freeware games that required an installation and were distributed by torrent. I have also owned games that were run by Steam - which just requires you to pay and log in - and have downloaded said games via torrent b/c I didn't have the disc with me at school. Those also required installation and were free. There are also probably games that you can buy online and download rather than getting a disc. Often times, companies offer their downloads via torrent (I know of several that do this).
Also, the user asking for help did not actually state that anything was in .rar packaging (or even in .iso or similar packaging), just that they had downloaded the game using a torrent and didn't know what to do now. Assumptions have been made that it was in .iso, .rar, or other similar packaging but they are not necessarily true. For all we know, it is a simple .exe but the user doesn't know which thing IS the .exe and which are other random files in the same folder that the program needs to run. Maybe they downloaded the torrent, it was a free game in .rar packaging but the user doesn't know how to use rar. Or even if they did, they already unrared it into a folder and now don't know how to start the program b/c they don't know which file is the .exe.
You shouldn't automatically assume that something is illegal going on based only on the fact that the question had to do with a game. No other real information was given so there is no way to tell. There's no need to lock the thread, advise illegal methods (such as cracks/keygens), or anything else.
What SHOULD be done is to ask the user to provide more information such as what the game is, if it is packaged, what file type is the packaging, etc.