Game Guy Room
The Game Guy Room is the gambling room run by Game Guy, which appears in Mario Party 3. When the player initially enters the Free-Play area, there is a note pinned to Game Guy's door (the red door near the exit) that says that access is limited to the Miracle Star. The player can play any one of the four Game Guy minigames once they are granted access. Game Guy also offers the player a special prize if they win 1,000 coins from him during a single stay in his room. Each time the player exits the room, their coins revert to zero. Therefore, they must remain until they win 1,000 coins. After the collection of 1,000 coins, Game Guy stops the competition and awards the player a special ??? minigame entitled Mario's Puzzle Party Pro. It is a one-player version of the 4-Player minigame Mario's Puzzle Party.
Since the player is told which minigame will be played before placing their bet, it is possible to strategize based on each game's characteristics. The ability to not go all-in every time (unlike when encountering Game Guy during regular play) makes going for a long-term profit using a high expected value is a viable strategy.
| Game | Odds of winning | Expected value | Notes |
|---|---|---|---|
| Game Guy's Lucky 7 | ≈ 52.01% | ≈ 1.72B | Values are assuming an even split between the four possibilities of how many rolls the two contestants make: 21/36 for 1.17B, 26/66 for 1.16B, 45/66 for 2.31B, and 51/121 for 2.23B. |
| Game Guy's Magic Boxes | = 50.00% | = 1.0B | Values are based on how going for double-or-nothing is equivalent to repeating the minigame, rather than changing the odds or winnings. |
| Game Guy's Roulette | = 28.57% (6/21) | = 0.5714B | Assuming a maximum win-rate, based on always betting on Koopa Troopa. |
| = 9.52% (2/21) | = 3.0476B | Assuming maximum EV, based on always betting on Toad. Betting on Game Guy has the same EV but half the win-rate. | |
| Game Guy's Sweet Surprise | ≈ 80.85% | ≈ 1.617B | Assuming a maximum win-rate, based on always betting on Big Chomp. |
| ≈ 57.60% | ≈ 2.0592B | Assuming maximum EV, based on betting on Little Chomp at ×16 and lower, and Big Chomp otherwise. |
