From the Super Mario Wiki
The Dueling Glove is an item that appears in both in Mario Party 2 and Mario Party 3, which allows the player to challenge another player to a duel in which they wager coins. The amount of coins is chosen by the user of the glove.
In Mario Party 2, the duel's minigame depends on the stage it is used on. As described in Mario Party 2's character descriptions, it is Wario's favorite item in the game, being the master of dueling; although this does not mean that the item is exclusive or appears more often for him. It reappears in Mario Party 3, where it has the same use, except that the duel minigames for it are more varied, not depending on the stage.