Playing D&D with myself

It is impossible to "roleplay" with yourself, as the interactive storytelling requires at least two people. However Dungeons & Dragons, especially 4th edition, is both a roleplaying game and a tactical combat game. And it is totally possible to play the tactical combat part against yourself. As a DM that has two purposes: Plain fun of exploring tactical options (although it isn't quite as much fun as playing with others), and preparation of your next adventure. You want every fight to be in

World of Warkraft...