2 | White plays one move, then black play twice,
3 | then white plays three moves...
6 At the very first move of the game, white make only one move - as usual.
7 However, after that and for all the game, each side must play as many moves
8 as the opponent just played plus one.
11 If a move gives check, then the sequence stops here, but the opponent can
12 still play as many moves as would be theoretically possible.
13 Also, if a checkmate or stalemate situation occurs before the maximal number
14 of moves are played, the game ends.
15 There are no en-passant captures.
17 figure.diagram-container
19 | fen:rnbqk2r/pppp2pp/4p3/8/1b1P4/4pN2/PPP1PPPP/RN1QKB1R:
20 figcaption "Mate in 1"
23 On the diagram white mates with the sequence of 5 moves c3 Ne5 Qd3 Qf5 Qf7.
24 Moves' notation is replaced by ∞ (infinity) when there are four moves
30 | You can start from the
31 a(href="https://en.wikipedia.org/wiki/Progressive_chess")
34 a(href="http://users.ics.aalto.fi/tho/chess.html") this page
35 | with several commented games.