Starts with the letter 'I'
- I-Chess. Large board variant that adds two more piece types: the wolf and the eagle. By Aurelian Florea.
- Idaidakama Shogi. Like Maka-Dai-Dai with drops and new pieces. (19x19, Cells: 361) By (zzo38) A. Black.
- Imperial Chess. Large variant with new pieces and victory by capture of royal pieces. (12x12, Cells: 144) By James Killian Spratt.
- In The Bin. Chess on a 9x9 board. Players select pieces from a bin. (9x9, Cells: 81) By Darren Izzard.
- Infinite Chess. Chess on on infinite board. Author: Hans L. Bodlaender. Inventor: Tim Converse.
- Infinite Chess. Extends Chess to larger, even infinite, boards. () By Tony Thomas.
- Insane Flip Relay Shatranj. Missing description (10x10, Cells: 100) By Michael Nelson.
- Insect Chess. On a 12x12 board. All pieces are insect and arachnid representations, with some unique pieces. (12x12, Cells: 144) By Tim Bostick.
- InterGrid Chess. Pieces on corners and on centers of squares of 8 by 8 board. (8x8, Cells: 145) By David Howe.
- Interloper Chess. Introducing the Interloper, a highly invulnerable attacking piece (with zrf). By M Winther.
- International Contemporary Random Chess. Missing description (10x10, Cells: 100) By Jose Carrillo.
- International Fischer Random Chess. Missing description (10x10, Cells: 100) By Jose Carrillo.
- Intrusive Squares. The board is split into 4 4x4 supersquares and reunited by 20 extra squares. (10x10, Cells: 84) By Charles Gilman.
- Invasion. A military inspired Chess variant played on an 84-squares board. (10x10, Cells: 84) By Jean-Louis Cazaux.
- IO Chess. Variant on 16 by 16 board with many pieces. (16x16, Cells: 256) By Mark Hedden.
- Irwell. Gain an advantage by crowning your enemy. (8x10, Cells: 80) By Charles Gilman.
Total items listed: 16