Kil-oni-Annu is a two-player board game in which the objective is to be the first to move all one's pieces safely across the board. The name is derived from the idea of competition between the Kildaroth and the Annunaki, and according to legend the game began as a nonviolent means of settling differences of opinion. The game is played with two sets of seven pieces. One set is white and the other is black. In most versions of the game, white is considered the Kildaroth and the black represents the Annunaki. The board is made up of two rectangular sets of boxes, one containing three rows of four boxes each and the other containing three rows of two boxes each, joined together by a "narrow bridge" of two boxes. Winning requires both skill and a bit of luck. Movements are determined by rolling a set of four-sided, pyramid-shaped dice. Two of the four corners of each die are marked and the other two are not, giving each die an equal chance of landing with a marked or unmarked corner facing up. The number of marked ends facing upwards after a roll of the dice indicates how many spaces a player may move during that turn. Gameplay is often extremely intense and can last up to half an hour. The object of the game is for a player to move all seven of their pieces along the course and off the board before their opponent. When a piece is on one of the player's own squares, it is safe from capture, but, when it is on one of the eight squares in the middle of the board, the opponent's pieces may capture it by landing on the same space, sending the piece back off the board so that it must restart the course from the beginning. This means there are six "safe" squares and eight "combat" squares. There can never be more than one piece on a single square at any given time, so having too many pieces on the board at once can impede a player's mobility. When a player rolls a number using the dice, they may choose to move any of their pieces on the board or add a new piece to the board if they still have pieces that have not entered the game. A player is not required to capture a piece every time they have the opportunity. Nonetheless, players are required to move a piece whenever possible, even if it results in an unfavorable outcome.