Escape From the Past : The Duke's Wrath (2nd ed.)

When nerd and gamer, Max Anderson, tries out an experimental computer game, he doesn't realize he's playing the ultimate history game, time-traveling into the past...anywhere...anytime. Survival is optional. To return home he must decipher the game's rules and complete its missions--if he lives long enough. To fail means to stayin the past--forever. 

Now he's trapped in medieval Germany, unprepared and clueless. It is the year 1471 and he quickly learns that being an outcast may cost him his head. Especially after rescuing a beautiful peasant girl from a deadly infection and thus provoking sinister wannabe Duke Ott. Overnight he is dragged into a hornets' nest of feuding lords who will stop at nothing to bring down the conjuring stranger in their midst.