| Falling block puzzle video game developed by Sega and released in the arcade in 1990. Ported to the Sega Mega Drive, Sega Master System and Game Gear. Due to its small size and low resale value, Columns was often included by Sega on compilation cartridges and CDs for the Sega CD system. It was also bundled with the Game Gear, making it the equivalent of Tetris for that platform. The definitive 16-bit version is Columns III. The most recent incarnation of Columns is the Game Boy Advance version, Columns Crown. The arcade and Sega Mega Drive versions are themed on Greek mythology, with jewels as the playng pieces. The Game Gear version has some alternative tile sets including fruit and dice.
The rules are simple. A column of three square pieces stacked one on top of the other is dropped into the play area. The player can move this piece left and right as it falls (as in Tetris), but cannot rotate it. Instead, pressing a button will cause the order of the blocks to shift by one position. The object of the game is to place columns at the bottom of the pit in such a way that lines of three or more same-coloured blocks are created (either horizontally, vertically or diagonally). When this happens, these blocks disappear, and any blocks resting upon them immediately fall in accordance to gravity. Often this will cause additional lines to be arranged, producing a cascade effect. The key to a long game (and therefore a high score) is to set up these cascades.
In two player competitive games, creating lines will cause problems for the other player (e.g. by pushing up the floor of their pit). In addition to these rules, there is also a 'special' column that occasionally appears. This will have the effect of immediately destroying all the blocks of the same colour as the one it lands on. (In versions with a two-player mode, the function can be switched by rotating the special column, to a mode that makes it remove several 'dead' lines.)
Most versions of the game have a level system that increases the speed of the falling blocks as each level is attained (and interestingly slows the pace a little if the height of the pile of blocks in the pit is significantly reduced).
The game has been cloned many times with shareware or public domain versions available for many non-Sega systems. | 
