An io9 Can't Miss Science Fiction and Fantasy title in March 2014.

Martin Banks is just a normal guy who has made an abnormal discovery: he can manipulate reality, thanks to reality being nothing more than a computer program. With every use of this ability, though, Martin finds his little "tweaks" have not escaped notice. Rather than face prosecution, he decides instead to travel back in time to the Middle Ages and pose as a wizard.

What could possibly go wrong?

An American hacker in King Arthur's court, Martin must now train to become a full-fledged master of his...

Ever since Martin Banks and his fellow computer geeks discovered that reality is just a computer program to be happily hacked, they ve been jaunting back and forth through time, posing as medieval wizards and having the epic adventures that other nerds can only dream of having. But even in their wildest fantasies, they never expected to end up at the mercy of the former apprentice whom they sent to prison for gross misuse of magic and all-around evil behavior.

Who knew that the vengeful Todd would escape, then conjure a computer game packed with wolves, wenches, wastelands, and assorted...