Bughouse chess and random to the casual onlooker; hence the name bughouse, which is slang for mental hospital. The game is traditionally played as a diversion from regular chess both over the board and online. Yearly, several dedicated bughouse tournaments are organised on a national and an international level. Bughouse is a chess variant played on two chessboards by four players in teams of two. Each team member faces one opponent of the other team. Partners sit next to each other and one player has black, while the other has white. Each player plays the opponent as in a standard chess game,
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