Mario Party: Dream Dice is a new game for the Nintendo NintePC, and takes a new feature of a "Dream Space", where if you land on the dream space, you go into a dream world where there is a special place to earn many mini-stars. However, randomly the dream world will be a nightmare world.
Mario and friends are having a slumber party, and they even invited Bowser this time! They are playing a board game, when suddenly the "Nightmare Spirit" bashes into the party and says- "Hello, mortals. We have set up a string of challenges for YOU. Let us see if you can beat them. Also, if he sets up anything to help you, you'll be sorry." he then, while disappearing, says "Also, Bowser, I borrowed some of your minions". They then appear in "Giant Town".