? Space

From the Super Mario Wiki

The ? Space is a green space typically found on the various game boards in the Mario Party. Ordinarily they activate special board-specific events that can change the outcome of a turn or even a whole game. In Mario Party 8, the shape of the space differs depending on the board, including the tutorial map. In-game, these spaces were known as Happening Spaces up until Mario Party 6, where the namesake was changed to Green Spaces for some inexplicable reason. In most games, a Bonus Star is awarded to the player that lands on more of these spaces than any other player at the end of the game.

Mario Party 1 and 2	Mario Party 3	Mario Party 4	Mario Party 5
Mario Party 6	Mario Party 7	Mario Party 8 (tutorial)	Mario Party DS

Spaces and Areas from the Mario Party series 1-Vs-3 Space 2-Vs-2 Space 4-Player Space ? Space Bank Space Basic Space Battle Space Blue Space Bowser Space Candy Area Capsule Space Challenge Space Character Space Coin Block Area DK Space Dice Space Duel Space Friend Space Game Guy Space Hex Area Item Space Koopa Kid Space Lucky Space Mic Space Mini-Game Space Miracle Space Mushroom Space Orb Space Power-up Space Rare Mini-Game Space Red Space Reverse Space Single-player Space Star Space Warp Space