2 | Every 20 moves, most empty squares freeze and isolated pieces vanish.
6 a(href="https://www.chessvariants.com/boardrules.dir/iceage.html")
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
13 figure.diagram-container
15 | fen:rnbqkbnr/pppppppp/cccccccc/cccccccc/cccccccc/cccccccc/PPPPPPPP/RNBQKBNR:
16 figcaption Deterministic initial position
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.
23 Just after the 20th black move (and before the 21st white one),
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.
29 If only one king remains, the other side loses.
30 But if both disappeared, then the result is a draw.
32 figure.diagram-container
34 | fen:2rq1rk1/3bpp2/1c1p1bP1/1p2n3/4P2P/1NN2P1c/PPPQ4/1K1R3R:
36 | fen:cccq1rkc/cccbppcc/cccp1bPc/ccccnccc/ccccPccc/cNrccPcc/PPPQcccc/1K1Rcccc:
37 figcaption Before and after 20...Rxc3
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".