Dredge is best described as a midrange deck with combo elements. Against interactive decks Dredge generates card advantage with recursive threats, while interacting with the board thanks to Conflagrate. It is described as having combo elements because of the occasional fast draw it can generate when it finds its Prized Amalgams quickly. How powerful Dredge is at any given point is often related to how much graveyard hate people are playing. If you can dodge seeing cards like Rest in Peace and Leyline of the Void, this deck is very good. You can read more about Dredge on Star City Games here and here.