Starts with the letter 'S'
- Sagittar Chess. Introducing the Sagittar, a bifurcation cannon related to the Korean cannon, on an H-board (zrf available). By M Winther.
- Samnis Chess. Introducing the Samnis, which combines rook-capture with bifurcated bounce-movement, on a Gustavian board (zrf available). By M Winther.
- Sankaku Shogi. Small Shogi variant played on a board of 44 triangles with no drops and a teleporting Emperor. (7x8, Cells: 44) By Larry L. Smith.
- Scout Chess. Introducing the Scout, combining queen-captures with Camelrider moves (zrf exists). By M Winther.
- Secutor Chess. Introducing the Secutor piece, and new collision-capture, on a Gustavian board (zrf available). By M Winther.
- SerPent Chess 50. Pentagonal cells form hexagonal blocks in two ways. (Cells: 50) By Charles Gilman.
- Shatra . Old game from the Altai from Russia, on special shaped board with draughts-like capture.
- A Silly 42-Squares Board. A Silly 42-squares board with a little Unirexial variant you can play on it. (Cells: 42) By Jared B. McComb.
- Singularity Chess. A fixed and fully notated form of singularity chess. By Aric .
- Slanted Escalator Chess. Chess on an asymmetric board with interesting connectivity. (8x8, Cells: 60) By David Short.
- Small Spherical Chess. Board of form of sphere, with 38 squares. (Cells: 38) By Andrea Mori.
- Snake Chess. A variant played on a 2 by 12 cyclindrical board. (2x12, Cells: 24) By Sergey Sirotkin.
- Snowflake Xiang Qi. A better Xiang Hex. (Cells: 140) By John Smith.
- Spacious Torus Chess. Chess on a toroidal board, using Ralph Betza's spacious pieces. (8x8, Cells: 64) By Jianying Ji.
- Spherical Guard Chess. Hiashatar (Mongol Grand Chess) on a spherical board. (10x10, Cells: 100) By Graeme C Neatham.
- spIndecision Beryl. Two players fight with three armies on board formed by 39 triangles. (Cells: 39) By Alexandre Muñiz.
- Spire orth triangular xiang-qi. Missing description (7x14, Cells: 98) By Daniil Frolov.
- Star of David 2 Level Hex Chess. An AOF offshoot on two side-10 triangles opposite ways round. (x2, Cells: 110) By Charles Gilman.
- Stelliform 6 player Chess. Stellisch from Wellisch, Stellicorn from Revergent, and Stellgi and Hexgi. (17x17, Cells: 121) By Charles Gilman.
- Step and Circle TrigChess. Trigonal entry for the 45 or 46 cell 2007 design contest. (9x6, Cells: 46) By Graeme C Neatham.
- Steps Chess. Board looking like steps of many stairs.
- Stheno Chess. Introducing the repulsive Stheno, which repels pieces as far as possible in the alignment direction (zrf available). By M Winther.
- Straights. Chess-like Naval Battle game from the end of the 19th Century. (9x11, Cells: 81) Author: John Reece. Inventor: Anne Marriot Watson.
- String Chess. A one-dimensional variant with a fairy theme. (1x24, Cells: 24) By Aaron Hall.
- Subway Chess. In a turn, player moves first middle subway part of board and then a piece. (7x7, Cells: 41) By Francois Tremblay.
- Sunflower HexChess. Hexagonal Chess in-the-round. (Cells: 120) By Graeme C Neatham.
- Swash. Different shaped boards. (Cells: 64) By Robert J. Bell.
- Symmetrical Chess Collection. Collection of several large symmetric chess variants with only line pieces. By Derek Nalls.
Total items listed: 28