This is what needs to be done for a true D&D movie, get some actors together and have them decide what kind of character they want to play and make their characters and pick back ground and such as well a description of said characters. Then play an adventure with them and afterwards have a set of writers adapt this to a movie. Keeping the feel of the rolls and such as well as anything said that would fit within the context of the game. This would let the actors have much more creative control over the said characters and give a chance to have some original characters added to the game worlds as well.