The Basics: Moving and Jumping
Figure 1 shows the basic starting position of a game of checkers: each player has twelve pieces, arranged on the dark-colored diagonals of an 8x8 square board. This example uses the official ACF colors-- green and buff squares with red and white pieces-- but other federations use different colors. Additionally, most checkers sets sold in the United States use black and red pieces & squares. Whatever color scheme is used, the dark-colored pieces (here, red) move first. Regular checkers ("men") may only move forward one square diagonally (Figure 2), and may likewise only capture ("jump") forward.
As shown in the figures above (taken from Jim Loy's Checkers Pages), a legal jump is only possible when the square immediately beyond the opponent's piece is empty. All jumps are forced in checkers, including jumps capturing more than one piece (Figure 4), though if more than one jump is possible a player may choose which jump to take. The forced-jump rule forms the basis of all tactics in the game of checkers, as it allows one player to control the tempo of the game and thus the position on the board.
Promoting Men to Kings
Similarly to chess, when a regular man reaches the opposite end of the board (called "kings row"), it is promoted to a king. Kings may move or capture either backwards or forwards, but otherwise behave the same way as men: the "flying kings" rule is not present in standard checkers. If a player promotes a man to a king by way of a jump into kings row, the turn ends as soon as the man is kinged, though the king must continue jumping the next turn if a legal jump is available. The tactic known as the "in-and-out shot" takes advantage of this rule, forcing one side to jump into kings row then immediately out of it, setting up a series of jumps for the other side.
In diagrams involving positions with kings (Figure 5), the king is generally represented by an extra mark (in some sets, the physical pieces have a crown on one side to indicate kings), though in tournament play a king is formed by stacking one piece of the same color on top of another. Kings are extremely valuable in most positions due to their flexibility, and often the chance to king a piece first is sufficient advantage to win a game.