5×6 chess
editQuickChess: Pawn double-move and castling are not allowed in this variant, pawns can only promote to captured pieces. The game was advocated as an educational tools for children to learn chess rules. The smaller board and less pieces would reduce the complexity of the game and allow for more quicker games.
Chess Attack: In this variant, pawns can make double-moves and en-passant capture is allowed. The game was endorsed by Magnus Carlsen and Alexandra Kosteniuk.