Circular chess of the board and a different starting setup. In the citadel game, if a king reaches the citadel, a draw is forced. The starting position is essentially obtained from that of orthodox chess by cutting the board in half and bending the two halves to join at the ends. Two lines are marked on opposite sides of the board, and each set of pieces is positioned so as to straddle this line. The king and queen start on the innermost ring, with, as is the case in square chess, the queen on a square of the same colour; the bishops
Three-dimensional chess by squares and often called "cells") alternate in color in all three dimensions. The horizontal levels are denoted by capital letters A through E. Ranks and files of a level are denoted using algebraic notation. White starts on the A and B levels and Black starts on E and D. White moves first. The game objective, as in standard chess, is checkmate. Rooks, bishops, and knights move as they do in chess in any given plane. Probably the most familiar 3D chess variant to the general public is the game of Tri-Dimensional Chess (or Tri-D Chess), which can be seen