Janggi (Korean: 장기, also romanized as changgi or jangki), sometimes called Korean chess, is a strategy board game popular on the Korean Peninsula. The game was derived from xiangqi (Chinese chess), and is very similar to it, including the starting position of some of the pieces, and the 9×10 gameboard, but without the xiangqi "river" dividing the board horizontally in the middle.

Janggi is played on a board nine lines wide by ten lines long. The game is sometimes fast paced due to the jumping cannons and the long-range elephants, but professional games most often last over 150 moves and so are typically slower than those of Western chess.^{[citation needed]}

In 2009, the first world janggi tournament was held in Harbin, Heilongjiang, China.

The board is composed of 90 intersections of 9 vertical files and 10 horizontal rows. The board has nearly the same layout as that used in xiangqi, except the janggi board has no "river" in the central row. The pieces consist of disks marked with identifying characters and are placed on the line intersections (as in the Chinese games xiangqi and Go). Janggi pieces are traditionally octagonal in shape, and differ in size according to their rank. The sides are Blue (or sometimes Green), which moves first, versus Red. Each side has a palace that is three lines by three lines (nine positions) in the centre of their side of the board against the back edge. The palace contains four diagonal lines extending outwards from the centre, forming an "X" shape.

The spacing between vertical lines is slightly wider than the spacing between horizontal lines. Therefore, the space created by the vertical and horizontal lines takes the shape of a slightly wide rectangle.

The pieces are labelled with Hanja. The characters on the red pieces are all written in the regular script while the blue/green pieces are all written in the cursive script.

The pieces that are equivalent to the kings in Western chess are actually referred to as generals (將軍 janggun) in Korean. They are labelled with the Chinese character Han 한 (in Chinese pinyin: Hàn; 漢) on the red side, and Cho 초 (Chǔ; 楚) on the blue side. They represent the rival states of Han and Chu that fought for power in the post-Qin dynasty interregnum period in China (see Chu–Han contention). In North Korea, the Chu–Han setup is not used; the red general there is called jang (將, "general") and the blue general is called gwan (官, "minister"). Both kings can also be referred to generally as gung (宮, "palace").

Janggi differs from its Chinese counterpart in that the janggi general starts the game from the central intersection of the palace, rather than from the centre intersection of the back edge. The general may move one step per turn along marked board lines to any of the nine points within the palace. There are four diagonal lines in the palace connecting the centre position to the corners. When the general is checkmated the game is lost. The general cannot leave the palace under any circumstances. If the generals come to face each other across the board, and the player to move does not move away, this is bikjang—a draw. This rule is different from that of xiangqi where it is illegal for the generals to face.