Switching Quests

[Krusiv]

Let's say I'm in normal act 3 and I want to re-fight the boss of act 1. If I go back to the act 1 boss quest will it overwrite my act 2 + 3 data and make me do those acts over again?

[Grunthex]

No. You could select the act I boss quest, run through and kill him, then exit the game and select your most recent act 3 quest. You would only lose any progress on the current quest.