I am asking this question primarily as a follow up to this question: Is creating and selling "cheats" or "hacks" for games illegal?
The consensus in that question seems that it is illegal to create derivative works from a particular copyrighted piece of software. However, with the rising popularity of Linux and open source software, proprietary game manufacturers are allowing their content to be run on open source systems.
It is universally accepted that I may modify a GPL program at will as long as if I distribute the modifications, I also distribute the changes to the source as well.
Now suppose I obtain a license to play a game in which I would like to cheat. I do not attempt to reverse engineer the game code or modify the program code directly. In fact my sole interaction with the game is running it consistent with the license. However, most programs rely on libraries. Most libraries such as libc or similar are open source. Could I modify the behavior of the function calls in such a way as to “cheat”? Would that be in compliance with the law?
What if I make modifications to the kernel or graphics drivers that prevent my graphics card from “properly” rendering the things on my screen? Is that a violation of the law?