Four-player chess - Wikipedia

3D Printable Hexchess 2 - 4-Player Chess Board - Borders and Tiles by Dalla Croce Studios

4 Player Chess: How To Play And Win

Four-player chess variants – Green Chess

Quadro Chess & Draughts - 4 player

Four-player chess - Chess Forums

WE Games Four Player Chess Set

4PC Variants List - Chess Forums

Large 4 Player Chess Set – Chess House

4 Players Chess Board

Three or Four Players Chess Set：A Leather Game Mat + 4 Packs of Pieces (64 Pieces) + 1 Game Manual + A Drawstring Storage Bag. A Strategy Chess Game for 2-4 Players : Toys & Games