For new or lapsed players, Master Duel's Solo mode is an effective if somewhat laissez-faire tutorial for the game's mechanics, unafraid to let you lose while unfolding feature after feature in a path that largely mirrors the progression of the game over the past 20 years. For current players, it offers cheesy-but-fun lore dumps about the cards, and a place to practice some of your new builds without risking your ladder ranking. In either case, expect to spend about 4-5 hours on the basics, and another 2-3 doing extra challenges and replays with custom decks. Not insubstantial, but if you're only looking for solo play, this might not scratch the itch.