Mario Party 4/Items

Items can be bought at the Item Shop, won in Mini Mini-Games, gotten from Mushroom Spaces, or won at the Lottery Shop. On Party Mode, a player can carry up to three items at a time. In team mode, you can also use your teammate's items. However, like on normal 4 player mode, in team mode you (and your own teammate) can only hold up to three items.

The player can hold up to three items in both modes of Party Tent (normal 4 player and team mode). If they (or their team) have too many items, they are not allowed to buy any more items from the Item Shop unless at least one of them (from their inventory) is used. (Later installments of the Mario Party series --after Mario Party 4-- starting from Mario Party 5 and up to Mario Party 8 and DS allow the player to hold up to six items on Team Mode but always up to three in normal 4 player.) On the Lottery Shop, if the player wins the 3rd prize (which is a Mushroom item), the owner of the Lottery Shop (Toad for Toad's Midway Madness, Goomba for Goomba's Greedy Gala, Boo for Boo's Haunted Bash, Shy Guy for Shy Guy's Jungle Jam, Koopa for Koopa's Seaside Soiree, or Koopa Kid for Bowser's Gnarly Party) will note that the player has too many items and they keep the Mushroom (and the player gets nothing).

Mini Mushroom
When the player uses this item, they become mini (tiny), restricts the Dice Block, and the player rolls one 1-5 Dice Block (for a total of 1-5 spaces). (This item lets the player roll 1-5 spaces instead of 1-10 --unlike the normal Dice Block). This item restricts the Dice Block like the Poison Mushroom from Mario Party 3. (However, instead of 1-3 --from Mario Party 3-- it's 1-5.) It also lets you can pass through pipes and/or play Mini Mini-Games. This item restricts the Dice Block however. This item costs 5 coins (if bought at an Item Shop).
 * Price: 5 coins

Mega Mushroom
Become mega (giant) and roll two dice blocks (for a total of 2-20 spaces). This is similar to the Mushroom from Mario Party 2 and 3. You steal 10 coins from every player you pass, but you skip board events and stars. You skip everything. However, the exception is Bowser on Bowser's Gnarly Party. If the player gets to Bowser while mega—from a Mega Mushroom—they get to do a Bowser mega minigame (Bowser Wrestling or Panels of Doom). Rolling the same numbers (two 1's, 2's, 3's, 4's, 5's, 6's, 8's, 9's, or 10's) is a bonus 10 coins, while rolling two "7's" is a bonus 30 coins. Unlike in Mario Party 2 and 3 (where rolling two "7's" is bonus 20 coins), rolling two "7's" with the Mega Mushroom is a bonus 30 coins.
 * Price: 5 coins

Super Mini Mushroom
If the player uses this item, they become mini (tiny) and roll two 1-5 dice blocks (for a total of 2-10 spaces). Like the Mini Mushroom, this item restricts the Dice Block. However, it is possible to roll the normal number of spaces with this item (2-10) just like the normal Dice Block (which moves 1-10 spaces). That is because there are two 1-5 Dice Blocks. (This item restricts the Dice Block from 2-20 to 2-10.) But you can't roll a total of "1". Rolling the same numbers is a bonus 10 coins (for two 1's, 2's, 3's, 4's, or 5's). This item, along with the Super Mega Mushroom, cannot be hidden on a Mushroom Space nor can its effect be inflicted on opponents by a Mini-Mega Hammer.
 * Price: 15 coins

Super Mega Mushroom
Become mega and roll three dice blocks (for a total of 3-30 spaces). This is similar to the Super Mushroom (from Mario Party 2 and 3). Like the Mega Mushroom, you skip everything (including Item Shops and the Star Space). However, the exception is Bowser on Bowser's Gnarly Party. If the player gets to Bowser while mega—from a Super Mega Mushroom—they get to do a Bowser mega minigame (Bowser Wrestling or Panels of Doom). Rolling the same numbers is a bonus 10 coins (for three 1's, 2's, 4's, 5's, 6's, 8's, 9's, or 10's). Rolling three "3's" is a bonus 30 coins, while three "7's" is a bonus 50 coins. This item (along with the Super Mini Mushroom) cannot be hidden on a Mushroom Space nor can its effect be inflicted on its opponents with a Mini-Mega Hammer.
 * Price: 15 coins

Mini-Mega Hammer
A randomly chosen opponent gets their effect inflicted by either mini or mega (from either a Mini Mushroom or Mega Mushroom) for their next turn. They are not able to use an item (if they have any items in their inventory) on their next turn. However, if they are mega —via a Mega Mushroom— they can skip everything (including Item Shops and the Star Space). If they are mini —via Mini Mushroom— they can play Mini Mushroom minigames and/or be able to enter Mini Mushroom Gates. The exception is Bowser on Bowser's Gnarly Party. The player (with the hammer) cannot inflict their own effect (Mega or Mini).
 * Price: 10 coins

Warp Pipe
Spin a roulette to determine which player you swap places with. These are useful when someone else is in range of the star or when you're the farthest player from the star.
 * Price: 10 coins

Swap Card
Spin a roulette to determine which player you swap items with. This is useful when at least two opponents have better item selections than you do.
 * Price: 15 coins

Sparky Sticker
Electrify the space you're standing on. The next player to reach the space will lose 10 coins and any mushroom effects.
 * Price: 15 coins

Gaddlight
If a player summons a Boo (either from a Boo's Crystal Ball or a Boo House), the victim player can use this item to scare away the Boo when he is after their coins or stars. The victim player, they are protected for one turn (with this item). And the Boo is not able to steal anything from the victim player. Then the player (who summons the Boo) ends up wasting 5 coins (to steal coins) or 50 coins (to steal a star) for nothing. They (who summon the Boo) end up wasting 50 coins (to steal a star) for nothing because they do not get to steal anything if the victim player has a Gaddlight. The Gaddlight will then disappear. If you try to use the Gaddlight at the beginning of your turn, you will be asked whether you wish to discard it or not. This can be useful if you have two other useful items and nobody else is in a position to send a Boo after you. However, on the board Boo's Haunted Bash, if anyone summons the Big Boo and chooses to steal something, this item does not work (even if all three targeted players have a Gaddlight).
 * Price: 15 coins

Chomp Call
The host and the Star Space moves when you use this item. Four Chain Chomps surround the host (when this item is used) and they scare them away to a different location. This is useful when somebody else is about to reach the star or the star is in a hard-to-reach spot.
 * Price: 15 coins

Boo's Crystal Ball
Lets you steal coins from another player for 5 coins or a star for 50 coins. The maximum number of coins the boo will steal is between 25 and 30 so this is a bad buy. However, it is a good prize in Mini Mini-Games. The victim can lose less coins from a Boo by pressing "A" repeatedly. The Boo steals up to 30 coins. The smaller number of coins that can be lost is 9 or 10. The most is 25-30. However, if the Boo steals a star (for 50 coins), the option to tap "A" is absent. If the victim has a Gaddlight, they can use the said item to chase the Boo away (when he is after their coins and stars). And the Boo, he steals nothing from the victim. Then the player (who summoned the Boo from the Boo's Crystal Ball) ends up wasting 5 coins (to steal coins) or 50 coins (to steal a star) for nothing.
 * Price: 25 coins

Magic Lamp

 * Price: 30 coins

The player summons a genie (known as The Genie of the Lamp) and he takes them to the Star Space. You still need to trade 20 coins for the star (unless the Last Five Turns event shows "Star Present" --where stars via the Star Space are free). If it's available (at an Item Shop) and you have 30 coins or more, buy it.

Item Bag
The Item Bag contains up to three unknown items. You will get as many items as you have room for. It's best to buy this when you're out of items but not headed for a Mushroom Space.
 * Price: 30 coins

Bowser Suit

 * Price: Only can be received by Bowser from a Bowser Space.

This item (when used) allows the player to dress up in a Bowser suit. The player rolls one Dice Block (for 1-10 spaces). They steal 30 coins from each player they pass. In Bowser's Gnarly Party, if the player gets to Bowser (while in a Bowser suit), Bowser gives them 50 coins.