Columns III is a competitive two player game. It includes a single-player mode with a series of AI opponents.
The area of play is enclosed within one of two tall, rectangular playing areas. Columns of three different symbols (such as differently-colored jewels) appear, one at a time, at the top of the well and fall to the bottom, landing either on the floor or on top of previously fallen "columns". While a column is falling, the player can move it left and right, and can also cycle the positions of the symbols within it. After a column lands, if three or more of the same symbols are connected in a horizontal, vertical, or diagonal line, those symbols disappear. The pile of columns then settles under gravity. If this resettlement causes three or more other symbols to align, they too disappear and the cycle repeats. The columns fall at a faster rate as play progresses. A player wins when their opponent's well fills up with jewels, which ends the match.