Jenga is a game of physical skill, marketed by Hasbro, in which players remove blocks from a tower and put them on top. The player who causes the tower to collapse loses. The word jenga is derived from kjenga the Swahili word for "build", jenga is the imperative form.

Jenga is played with 54 wooden blocks; each block is 3 times as long as it is wide, and slightly smaller in height than in width. The blocks are stacked in a tower formation; each story is three blocks placed adjacent to each other along their long side, and each story is placed perpendicular to the previous (so, for example, if the blocks in the first story are pointing north-south, the second story blocks will point east-west). There are therefore 18 stories to the Jenga tower. Since stacking the blocks neatly can be tedious, Hasbro includes a loading tray.

Once the tower is built, the person who built the tower moves first. A move in Jenga consists of taking one and only one block from any story below the highest completed story, and placing it on the topmost story in order to complete it. Only one hand at a time may be used to remove a block; both hands can be used, but only one hand may be on the tower at a time. Blocks may be bumped to find a loose block that will not disturb the rest of the tower, but any block that is moved out of place must be replaced (still with one hand) before examining the tower further. The turn ends when the next person to move touches the tower, although he can wait 10 seconds before moving for the previous turn to end.

The game ends when the tower falls in any significant way -- in other words, any piece falls from the tower, other than the piece being knocked out to move to the top. The loser is the person who made the tower fall (i.e. whose turn it was when the tower fell); the winner is the person who moved before the loser.

The game in its current from was invented in the 1980's by Leslie Scott. It grew out of a childhood game created around a present of wooden building blocks purchased from a local wood craftsman in Ghana.


Variants
Throw 'n Go Jenga is a variant marketed by Hasbro. It consists of blocks that are colored red, blue, or yellow plus a six-sided die. Before each move, the player throws the die and then follows the instructions on the die:

Yellow/End: Remove any yellow block or remove any color end block. 
Red/Mid: Remove any red block or remove any color middle block. 
Blue/End: Remove any blue block or remove any color end block. 
Any two: Remove any two blocks of any color in any position. 
Wild: Remove any color block in any position 
Reverse: Don’t remove any blocks, but pass the die to the next player in the opposite direction. 
Other than the fact that the die determines the proper move, play continues the same as regular Jenga.

Jenga Debate combines the atmosphere of a courtroom with the classic Hasbro family game. This cult variation of Jenga (invented initally by two students in the south of France) involves corresponding each pre-numbered block with different types of a theme. The most popular theme is that of celebrities, where the aim is to argue the case for whether a celebrity is good or bad. When one of the numbered blocks are removed, the players check which figure (such as a celebrity or a historical figure) corresponds to that number. The person who picked the block then takes on the role of defendant - making a maximum of 5 points to support their claim that the figure they're defending is a 'good' person. The opponent (acting as prosecutor) must argue against this. If the defendant fails to convince the other players (acting as a jury) that the figure for debate is good then he/she must have another go (and thus increasing their risk of losing the game by toppling the tower). If, however he/she succeeds then the prosecutor is forced to play. Not all of the blocks are up for debate; some are pre-decided as good or bad for the purposes of variation. All of the original rules of Jenga still apply and the person who topples the tower is out of the game.

Jenga Truth or Dare is an adult variation of Jenga also marketed by Hasbro. This version looks like regular Jenga except there are three colors of blocks, red, black and natural, instead of just the natural color of Jenga. Play is the same, but if you move a red block on your play, you have to complete the dare printed on it before stacking the block on top. If you move a black block, you have to truthfully answer the question printed on the block before stacking it. The natural blocks have nothing printed on them and are played as in Jenga. However, it is permissible to write your own truths or dares on the natural blocks if desired.

Jenga Extreme uses blocks with different shapes and angles instead of the rectangular blocks of Jenga.

Drinking Jenga is a home-made variant using the standard Jenga game. Played at a party, each of the tiles has a command written on the bottom. The commands usually involve drinking or doing something embarrassing, from simple commands such as "Take a Drink" or "Give Away 2 Drinks" or "Do a Funky Dance Move," to more complicated commands such as "Look at someone, and try to get them to say "What?" If they do, they have to drink. If they don't, you have to drink."

When a player takes a tile, they must obey the command written on the bottom. The remainder of the game is played in the standard way, with the loser (the one who collapses the tower) drinking an entire beer.

First Touch Jenga is a variantion on the basic rules whereby the player must remove the first block they touch, whether or not the block can be easily removed. Players must still use one hand, but may use other digits to prevent other blocks moving as they take their turn. The dynamics of the game change dramatically using the additional rule: players will consider their choice more carefully, examine the weighting distribution. The tower often becomes distorted and rotated as players forcefully remove difficult blocks, adding to the complexity of making a move.