Why do you say "for the browser"? Unless you are working on a system with a ludicrous amount of effective DRM (which I hope we all hate for other reasons, and w

Why do you say "for the browser"? Unless you are working on a system with a ludicrous amount of effective DRM (which I hope we all hate for other reasons, and which means we are only really talking about consoles: the closest casual gaming platform you are going to get to "locked down system owned by the manufacturer" is an iPhone, and in practice they don't go quite far enough), players are always going to be able to modify your code: you can't prevent a user "cheating" (which I put in quotes, as I feel like you need to really question whether the environment you set up where that matters isn't somehow itself broken; maybe you are already doing that by "source-like networking", but I don't know the terminology context).