Boo's Haunted Bash takes place in a Haunted House-type setting that is located in the woods. The board is home to a variety of spooky characters and objects. The character can find eerie trees, floating furniture, and Boos that are scattered around the map. The map's main feature is the Mystery Train and a select few paths that are guarded by Red Boos. When the Red Boos are present on the board map, they will create a few bridges that can be found at a few conjunctions. If a character passes through the Red Boo's altar at the center of the board while they are present, the Red Boos will disappear along with the bridges that they create. The characters will be able to ride the Coffin Train at the top of the board once the Red Boos vanish. The Mystery Train allows other characters to ride to certain parts of the board.
Notable Characters and Events
- Red Boo's Altar - At the center of the board, a giant Red Boo can be seen floating on an structure that resembles an altar. If the character passes by the altar while the giant Red Boo is present, the giant Red Boo will vanish along with the other Red Boos. If they vanish, then the character's will not be able to access certain paths on the board. A character can pass by the altar to force the Red Boos to reappear.
- Mystery Train - At the top of the board, there is a mini graveyard that belongs to a normal Boo. Once the Red Boos vanish, the characters have the option of riding the Mystery Train for no charge. The Mystery Train will produce 4 coffins and take the characters across the board, passing by empty chasms and a few conjunctions. If the train makes contact with another character on the way, they will be forced to ride the train. The characters will not be able to access the train if the Red Boos are present.
- Big Boo Grandfather Clock - At the top of the board is a large clock with a timer in front of it. Everytime a character lands on the happening spaces near the clock, the clock will then start to countdown from three. If the timer reaches zero, then Big Boo will appear and steal coins from all the opposing characters for 15 coins or steal a star from all the opposing characters for 150 coins. Once Big Boo has been summoned, the timer will reset back to three. Big Boo can only be accessed when the Pink Boos are present, as the Coffin Train passes by the happening spaces when a character decides to ride it.
On each board map in Mario Party 4, there are two sets of mini-games that a character can access with the use of a Mini Mushroom. The mini-games cannot be played if the character is normal or giant size.
- Trumpet Game - The first mini mini-game can be found near the Red Boo's altar. During this game, three items will be inserted into a trumpet and be randomly scrambled. The character will have an option to jump on one of the trumpet buttons, releasing an item from the mouth of the instrument.
- Piano Game - The second mini mini-game can be found near the grandfather clock at the top of the board. The mini-game involes the use of a piano to collect coins.
- Boo's Haunted Bash has the fewest happening spaces out of any Mario Party game. The board consists of two happening spaces that sponsor one event.
- The Big Boo that can be found at the grandfather clock at the top of the board is similar to the Big Boo in Horror Land in Mario Party 2. They both charge the same fee for stealing coins and stars, and they both steal from all the opposing characters.
- The Mystery Train is similar to Steamer from the Western Land map in Mario Party 2.