Serialized online story about people creating a death sport after an AI makes everyone immortal

Several years ago (4-5?), I read a story online that I believe was still being actively being published in a serial format.

The principle idea, as I recall, was that an artificial intelligence determined that it could essentially prevent people from dying altogether by suffusing everything with nanomachines (or something to that effect). The end result was that, years after the fact, a group of people made a sport of trying to kill themselves in increasingly inventive ways, with an ultimate goal of finding a loophole that allows them to die before the AI can prevent it. I think one of the main characters was the oldest woman on Earth prior to everyone becoming immortal, but that may be a different story.

I can't recall what the name of it was, and every attempt to google anything with 'AI' in the search just gives a bunch of current news articles. Thanks for the help!

Answer

As per Short story about a virtual world. Protagonist is a female who specializes in torture experiences, this is The Metamorphosis of Prime Intellect, a novella by Roger Williams.

To quote FarfieldDino's answer:

A computer of omnipotent power that is (theoretically) benevolent to humans controls the physical universe as though it were a virtual simulation. Humans can't be hurt, but some get bored. They exploit a loophole in the computer's logic and create self-contained game worlds where the safeties are turned off. The object is to survive as long as possible and the only escape is death. When they die, they are resurrected outside of the game.

The main character (the woman) is the best player of these games, and is known as the 'queen of the death jockeys'. At one point she does critique a new game maker's game early in the story.

And it is available here.