So, with a series, is it neseccary for the main character to be of any importance, have a mysterious past?

The main character should be of some importance, he is the main character after all. I think you can write about an Average Joe, but being the main character in enough not-so-average events should sort of bring him above the average. Because I think main characters should be able to overcome challenges that most people will never even face.

Does he need to have a mysterious past? Well, that depends on the type of series you want to write. Do you want your main character to keep discovering new things about himself or his family as the series progresses? Do you want the mysteries to be more about discovering something new about the world in which he lives? Or some combination of both? So, no, I don't think it's necessary for the main character to have a mysterious past, unless that's the kind of series you want to write.

Could a series be based on a relativly normal guy in a sequence of events?

Sure, why not? See above about Average Joe.

Does the importance/danger level of the plot need to increase?

Again, I think this depends on the type of series you want to write. Within each book, the danger level should increase until you get to the climax. And I think you can set up a series like this, where you think of each book in the series as a different act, so the danger level will increase until you get to the final book or the climax of the series. But then you can also write a series where there is no overarching plot, so the danger level wouldn't have to increase with each book in the series.

Another thing to keep in mind is how much you want your main character to grow and develop. So I would choose whichever works best for telling your character's story.

Yttar