>>52084751It doesn't, not in a linear way. It hand holds you a lot at the beginning but then you unlock the three main storylines and your map fills with icons, you are encouraged to purse them in any order, but there is a set order of escalating levels that the game doesn't tell you. The stuff closest to the starting town tends to be easier, but the further you venture out the more of a crapshoot it becomes.
Some anons worked out a rough order going by levels in pic related.