| 1 | p.boxed |
| 2 | | Every 20 moves, most empty squares freeze and isolated pieces vanish. |
| 3 | |
| 4 | p |
| 5 | | Ice Age is a |
| 6 | a(href="https://www.chessvariants.com/boardrules.dir/iceage.html") |
| 7 | | chess variant |
| 8 | | invented by Köksal Karakus in 2000. |
| 9 | | It can also be played on |
| 10 | a(href="https://brainking.com/en/GameRules?tp=100") brainking.com |
| 11 | | . |
| 12 | |
| 13 | figure.diagram-container |
| 14 | .diagram |
| 15 | | fen:rnbqkbnr/pppppppp/cccccccc/cccccccc/cccccccc/cccccccc/PPPPPPPP/RNBQKBNR: |
| 16 | figcaption Deterministic initial position |
| 17 | |
| 18 | p. |
| 19 | If the board is filled with ice cubes, you can only move by capturing them. |
| 20 | Ice cubes behave as normal pieces, which cannot move. |
| 21 | |
| 22 | p. |
| 23 | Just after the 20th black move (and before the 21st white one), |
| 24 | "ice age is coming": |
| 25 | ul |
| 26 | li all empty squares freeze, except those orthogonally surrounded by pieces. |
| 27 | li all pieces which are not adjacent to any other piece (black or white) vanish. |
| 28 | p. |
| 29 | If only one king remains, the other side loses. |
| 30 | But if both disappeared, then the result is a draw. |
| 31 | |
| 32 | figure.diagram-container |
| 33 | .diagram.diag12 |
| 34 | | fen:2rq1rk1/3bpp2/1c1p1bP1/1p2n3/4P2P/1NN2P1c/PPPQ4/1K1R3R: |
| 35 | .diagram.diag22 |
| 36 | | fen:cccq1rkc/cccbppcc/cccp1bPc/ccccnccc/ccccPccc/cNrccPcc/PPPQcccc/1K1Rcccc: |
| 37 | figcaption Before and after 20...Rxc3 |
| 38 | |
| 39 | p. |
| 40 | Then, every 20 moves ice age comes again: after move 40, 60, and so on. |
| 41 | This condition excepted, the game follows FIDE chess rules, without draws |
| 42 | on repetition: indeed, as the author notices, sometimes a win is possible |
| 43 | by "waiting until the enemy king freezes". |