Boo's Haunted Bash (JP) is a haunted house themed board from Mario Party 4, hosted by Boo. He built it because he loves scaring people, and wanted his friends to be scared here as much as possible. It has a difficulty of 2 out of 3.
The main gimmick in this stage are the disappearing bridges.The Big Red Boo in the center of the board changes which controls if the bridges are there or not.
The Mystery Train brings the players to the graveyard on the other side. The player can control which way the train goes. The players that are in the way get on the Mystery Train and ends on the same space as the rider. The Boo controlling the Mystery Train will not give rides if the bridge is there.
The Item Minigame involves a large trumpet with the items going into the trumpet and the player choosing one of the 3 buttons to step on and get the respective item. The Coin minigame involves the piano where the player has to copy the Boo's movements with the right button. The more keys hit correctly, the more coins the player can get.
The only Happening Spaces are in the top-right which turn a clock. After 3 times, it summons the Big Boo. The Big Boo can steal Coins or Stars from the other players and give it to the player that summoned him. The Gaddlight does not work on him.