Starts with the letter 'S'
- Sentinel Chess. Instead of queens, players have sentinels who can transform into 8 pawns. (8x8, Cells: 64)
- Separate Realms Chess. Pieces capture like normal FIDE pieces, but have limited moves that only take them to part of the board when not capturing. (8x8, Cells: 64) By Peter Aronson and Michael Nelson.
- Separate Realms Chess II. A Variant of Separate Realms Chess with standard FIDE King, and more powerful Knights and Queens. (8x8, Cells: 64) By Jörg Knappen.
- Shamanic Chess. Pieces may be transformed into 'Shamans'. By M Winther.
- Shambhala chess. Maybe, it's the misterious first form of chess? Actually, most probably, not. (8x8, Cells: 64) By Daniil Frolov.
- Shatar, Old 1 Hia. Old Shatar with one Hia. (8x8, Cells: 64) By Gary K. Gifford.
- Shatranji. Missing description (8x8, Cells: 64) By Fergus Duniho.
- Shogun Chess. Pieces promote and can be dropped, similar to Shogi. By Daniel Lee.
- Simplified Chess. Missing description (8x7, Cells: 56) By John Kipling Lewis.
- Sirlin's Chess. Alternative presentation of "Chess 2 - The Sequel". (8x8, Cells: 64) Author: (zzo38) A. Black. Inventor: David Sirlin.
- Sonic the Hedgehog Chess Advanced version. Missing description (8x8, Cells: 64) By Daniil Frolov.
- SquireKnight. Squire Knight combines Knight and Forward/Backward Pawn like moves. (8x8, Cells: 64) By Stephane Burkhart.
- Sting. A game where Kings can move like Grasshoppers in addition to their normal move. (8x8, Cells: 64) Author: Hans L. Bodlaender.
- Strong Pawn Chess. Pawns move in a similar fashion to the pieces they start in front of. (8x8, Cells: 64) By Este.
- Stupid. A cross variant between Ultima and orthodox chess. (8x8, Cells: 64) Inventor: Paul Monckton.
- Superchess. Pieces can be put on top of rooks and moved with them. (8x8, Cells: 64) By John Montagna.
- Superhero Chess. Major pieces are superheroes, pawns their (interchangeable) sidekicks. (8x8, Cells: 64) By Daniel Robert MacDuff.
- SuperKing. Kings move like queens and leap over friendly pieces, but cannot move through check. (8x8, Cells: 64) Author: John Love-Jensen. Inventor: John Love-Jensen and Richard .
- Swap Chess. A move can consist of a series of pieces swapping places. (8x8, Cells: 64) By João Pedro Neto.
- Swapmate Chess. Pieces have "mates" which they can swap places with. (8x8, Cells: 64) By Adrian Alvarez de la Campa.
- Switching Chess. In addition to normal moves, switch with an adjacent friendly piece. (8x8, Cells: 64) By Tony Quintanilla.
- Switching Realms Chess. All noncapturing moves must change the board subset a piece occupies. (8x8, Cells: 64) By Jörg Knappen.
- Synchronous Chess. Chess played with written simultaneous moves. By Ralf Hansmann.
Total items listed: 23