It seems to either be random or with each character having their own deck that allows you to upgrade. There is a picture of a dagger, sword to magic sword upgrade path. I am really not sure what it is. I am not going to say this is better or worse than what is out there. I have not looked into the rules enough to make any sort of judgement. If you have Super Dungeon Explore you may like that better and do better just getting an expansion. I am not sure so please do your own research into the rules.
I am not going to say this is a cheap investment as the stretch goals all depend on a $100+ investment. The thing is when you do that you are getting tons of extra minis. From an extra skeleton expansion to more of the basic and captain level troops. But it just keeps going with new adventures and bosses coming on too. The thing is they still have 8 days to go and will probably get a few more of these delivering a game and enough extra material to keep you going for a long time.
Personally adding the Skald and the basic $100 investment would give my group enough game play to get sick of the game. That is a good thing!
Update: here is a great little visual to see what you get , still thinking about this one ugh, need a new vid card too.