? Block

The Question Block (also known as the Mystery Block in Super Mario Land and the Prize Block in Super Mario World) is one of the many blocks found in the Mario universe, and one of the most common. Question Blocks are usually seen floating in midair, often containing Gold Coins, Super Mushrooms, or Fire Flowers. In some games (for example Paper Mario and Mario & Luigi: Superstar Saga, as well as several classic platformers) there are some invisible Item Blocks. Super Mario Bros. 3, the game shows different ways to hit the block other than simply punching it from below. One example is when Mario or Luigi use the Tanooki Suit, the Mario bros. can use their tails to whack the Question Block. Another example is by using the Koopa Shell, when Mario or Luigi kick the Koopa Shell to the Item Block; the Item Block will pop out containing a Coin or an item. In New Super Mario Bros. and New Super Mario Bros. Wii, a Ground Pound may also be used.

Much mystery enshrouds the Question Blocks, and little detail has been given about their origin. Super Mario Bros., however, gave the explanation that Bowser, using the Koopa Clan's famous dark magic, had cursed the Mushroom Kingdom, turning its citizens (presumably the Toads) into a variety of objects, including bricks (which the Item Blocks could alternately be thought of as). The game's manual later talked about how Mario could "come across Mushroom People who had been turned into bricks" and receive items from them. Although this is the only official history origin of the Item Blocks, it would appear to have been long retconned out of official Mario games, with Question Blocks now seemingly being a natural feature of the Mushroom Kingdom. Item Blocks are not to be confused with Exclamation Mark Blocks, which are similarly floating blocks.

Super Mario Bros.
Super Mario Bros. was the Question Block's debut appearance in the Mario series, along with a handful of other items. They appeared to be flashing and they gave Mario either coins or items that can help Mario. They are very common, since they are sometimes needed to complete a level or help Mario in a tough situation. Some blocks are hidden and can be only seen when Mario happens to hit them.

Super Mario Bros.: The Lost Levels
These blocks reappeared in Super Mario Bros.: The Lost Levels with the exact same appearance and function. Because of that, no changes has been made to these blocks.

Super Mario Bros. 3
Question blocks had a slightly different design change; they were no longer flashing and the ? marks on the blocks seem to be moving in the game, Super Mario Bros. 3. They still cough up coins and other items that can help Mario when hit upon.

Super Mario World
The Prize Blocks of Super Mario World had eyes and seemed to be reanimations of that game's Turning Blocks. They also gave Turning Block-like angry eyes when hit; these expressions-when-hit are often seen even in non-eyed Question Blocks today, making the Prize Block a possible relative of the Turning Block. Otherwise, no function-related changes has been made, but some blocks can release sprouts into the air, making it available for climbing.

Super Mario Land
Question Blocks could be found once again in Super Mario Land. Here, they serve the exact same purpose and function as the previous games they appeared in.

Super Mario 64 DS
In Super Mario 64 DS, red Question Blocks replace the red, blue, and green ! Blocks. They are initially transparent, and had to be activated by hitting the ? Switch. They contain either Power Flowers, Feathers or Bob-ombs, depending on character and hat status.

New Super Mario Bros.
In New Super Mario Bros., red flying Question Blocks fly around the world map, moving to different levels every time Mario or Luigi die or complete a level. Five items can be inside: a Fire Flower, 1-Up Mushroom, Mini Mushroom, Mega Mushroom, or a Blue Shell. Also in two Ghost Houses, Question Blocks that contain Boos appear. The original yellow Question Blocks also appear and the vine sprouting blocks make an appearance again.

Super Mario Galaxy
In Super Mario Galaxy, Question blocks contained Star Bits and coins, and could usually be hit multiple times before vanishing. If the player manages to hit a Question Block with star bits enough times, it would, as aforementioned, vanish, though when it does a multitude of star bits will scatter across the stage.

New Super Mario Bros. Wii
The Question blocks make a return in New Super Mario Bros. Wii. Here, they have the exact function and appearance as in New Super Mario Bros. but some behave differently from the average Item block. In some levels, for example, some blocks tend to sway left and right along with other objects such as brick blocks and coins. Others lay in the water in some levels, where it is easier to ground pound them.

Paper Mario Series
In the Paper Mario series, Red Question Blocks contain badges and yellow ones contain coins or items. Question Blocks are sometimes invisible at first. They are turned visible by jumping into them (or using Watt in Paper Mario). Once they're visible, they can also be used as stepping stones.

In Paper Mario: The Thousand-Year Door during Bowser's event, Meat will come out of the Question blocks. If the player obtains four of these Meats, Bowser will grow huge, allowing him to smash through objects.

Mario Kart Series
In the Mario Kart series, from Mario Kart 64 and onwards, similar item blocks, called Item Boxes are found on every track. However, they are usually not flying up in the air but they are floating on the ground and they are usually semi-transparent and reappear when they get hit.

In Mario Kart Wii, on the track Coconut Mall, there is shop that is selling Question Blocks along with other classic Mario items. In the track Grumble Volcano, there are giant Question Blocks on some of the sinking mountains, along with regular Brick Blocks.

Super Smash Bros. Series
Question Blocks make an appearance as objects in the latter two games in the Super Smash Bros. series. In Super Smash Bros. Melee, Question Blocks appeared on the Mushroom Kingdom stage and could contain items if attacked or simply smashed from below. They also appear in Super Smash Bros. Brawl in the Mushroom Kingdom stage, with the same purpose.

Mario & Luigi Series
Question Blocks were one of many types of block to appear in the Mario & Luigi series. They can give Mario and Luigi coins or items that can help them, similar to the series the blocks normally appear in. One hit on, they turn brown and they won't offer any more items. If Mario and Luigi happens to have 99 of the item found in the block, the item will remain in the block.

In Mario & Luigi: Superstar Saga, there is a room in the Woohoo Hooniversity which is designed to study different kinds of Question Blocks. The blocks found in this room are from Super Mario Bros., Super Mario World, Paper Mario and Super Mario 64.

Mario & Luigi: Bowser's Inside Story featured a character named Broque Monsieur, who appears to be made from Question Blocks. Some other characters also appeared to be made from blocks.

Trivia

 * In Yoshi's Story, there is mini-game game called Melon Race in which Yoshi must hit a Question Block and race a melon-eating Chain Chomp.
 * The Question Block is a piece of furniture that the player can buy in the game Animal Crossing for the Nintendo GameCube.
 * In all Nintendogs games, it is possible to get a Question Block item.