I think the book you're talking about is The Metamorphosis of Prime Intellect. I just finished reading it, and the question is a very succinct summary of the plot. Asimov's 3 laws are deeply woven into the book, almost as much as they are in I, Robot. Additionally, the book opens with the main character in a death game, and significant time is spent explaining the relationship between the death games and the 3 laws.
There's a good enough plot summary on the Wikipedia page to sound familiar to someone who'd read the book before, and copies of the text are available for free online (legally). (You can also buy a hardcopy.)