A lot of people get confused with how Auto Deck Builder operates, I think the explanation should be made a lot clearer so people understand what they are getting when they put down money for it. Myself I am happy with my lifetime purchase as this is a great bot and I've got more than my $$ worth out of it.

The way Deck Builder works is it has many thousands of decks in its catalogue however it will ONLY suggest a deck for you if you have EVERY card in that deck, this is where a lot of people get confused and the main problem lies. For example, I was very lucky and pulled a Dr. Boom in one of my first ever packs, so basically I had Dr. Boom and then a lot of basic cards/some naxx and not a lot of other good key cards (missing Knife Juggler etc.) So when I put in the filter "Must have Dr.Boom", it always returned "No decks available". This is because all the decks in Deck Builder's catalogue that contained Dr. Boom also had all the other key good cards (Knife Juggler etc.) that I didn't have because whoever made those predefined decks assumed that if you were good enough to have Dr.Boom you were good enough to have most of the other decent cards.

Deck Builder is awesome if you have all the necessary good cards because then there are lots of decks in Deck Builder's catalogue which will match with your collection and it will give you a good amount of suggestions. If you're like me though and are missing lots of cards in your collection then the best option for you is to not try and put legendaries in the filter, rather put the cards that you do have that aren't legendary in the "must use at least one of" column then Deck Builder will still give you a few different deck suggestions with the cards you've chosen, then just swap out some of the minions it uses with ones you'd prefer and add your legendaries.

I hope this makes sense, I was also quite confused when I first bought hearthranger but I think this will be a tool that becomes more useful for me as I get more cards.