Mario Party 4 reverted back to the simple amount of items similar to the second game in the series. In total, there are 13 items. You can hold up to three items at a time.
When used, this mushroom allows you to grow twice your size and gives you two dice blocks to use instead of one. Any players that are passed and crushed and 10 coins are taken away and then given to you. The downside to this item comes when you cannot stop by any board events (including the shops, lottery, star space, etc.)
The Mini Mushroom shrinks your size and allows you to maneuver through the various pipe paths found on each board. Your dice roll will be limited to 5 and the mini board events can be accessed.
Super Mega Mushroom
The Super Mega Mushroom has the same effect as the Mega Mushroom save for the fact that you get three dice blocks to roll instead of two.
Super Mini Mushroom
With this item you get two 1-5 dice blocks instead of one. All other effects are the same as the Mini Mushroom.
When used, a roulette wheel appears with the other three character’s faces on it. The wheel will spin and you will warp to the character’s space that is chosen.
Just like the Plunder Chest from previous games, the Swap Card allows you to trade items with another player.
Mini Mega Hammer
This item allows you to select another player and have them hit with the hammer. The hammer will randomly affect the player by either shrinking or growing the player. The effects for the other player won’t start until their next turn.
This sticker is placed on the current space you are standing on. It causes anyone who passes it to lose 10 coins and takes away any mega or mini effect.
Four Chain Chomps will be summoned to the star spot when this item is used. The host of the board will be scared off to another location, thus changing the location of the star space.
Boo’s Crystal Ball
Using the crystal will summon Boo to your space. Boo will offer his services of stealing coins from another player for 5 coins or stealing a star from another player for 50 coins.
Having this item in your item inventory will protect you from any of Boo’s attacks. This item will be used automatically and is good for one use.
Using the item bag will grant you three random items assuming you do not have items in your item inventory.
The Magic Lamp will call the Mushroom Genie to your aid. He will transport you directly to the star space. However, you still need 20 coins to purchase the star.
A rare item that can only be obtained when landing on a Bowser space. The item will transform you into a Bowser look a like and allows you to steal 30 coins from any player you pass.