Includes

Bars

2009-10-23

Time Chess

Imagine a 6-turn cycle of turns in regular chess. These six "phases" represent times of day. There are three different types of phases:
  • Day = During Black's daytime turn, Black can only see Black pieces (day blindness)
  • Twilight = Both players can see all pieces
  • Night = During White's nighttime turn, White can only see White pieces (night blindness)
There are two turns, one black and one white, in each type. The arrangement is such that each player once a round has no idea what their opponent's last move was. This introduces a great deal of uncertainty to the game.

  1. "Dawn" (Twilight ~ 04:00-08:00)
    • Black's move.
    • Everyone can see all pieces (no one is blind).
    • Black can see both Black and White pieces.
  2. "Midday" (Day ~ 08:00-12:00)
    • White's move.
    • Black is blind during the day.
    • Black can't see White's pieces.
  3. "Evening" (Day ~ 12:00-16:00)
    • Black's move.
    • Black is blind during the day.
    • Black can't see White's pieces.
    • Black may not know what move White just made.
  4. "Dusk" (Twilight ~ 16:00-20:00)
    • White's move.
    • Everyone can see all pieces (no one is blind).
    • White can see both Black and White pieces.
  5. "Midnight" (Night ~ 20:00-00:00)
    • Black's move.
    • White is blind at night.
    • White can't see Black's pieces.
  6. "Morning" (Night ~ 00:00-04:00)
    • White's move.
    • White is blind at night.
    • White can't see Black's pieces.
    • White may not know what move Black just made.
Phase 1 ("Dawn") is always first.

NOTE: Since the only time your opponent cares what the board looks like is after you've made your move (that is, once the state of the board has actually changed), a videogame version of Time Chess can assume discrete phases as opposed to continuous ones.

It's recommended that when playing in real life, that you use two chess boards, one complete set of chess pieces, and a suitable opaque divider for hiding a chess board when necessary. All white pieces would be on one board (i.e. "White's board"), and all black pieces would be on the other board (i.e. "Black's board"). It's also recommended that the players keep track of what phase the round is in by some method, such as a pen the tip of which represents a 24hr clock hand. During a person's blind turn, the non-blind player can legally peek over the divider separating the boards. During twilight phases, the divider is pointless. Naturally, you must implicitly trust that your opponent won't cheat. A computer version of this game would make that a certainty.

Other than these visibility rules, Time Chess plays just like regular chess but with a few exceptions:

  1. Any pawn move in a player's "blind" turn is reversed (forfeited) if the move is blocked by another piece being in the way, because a pawn can only capture diagonally.
  2. When coming out of a player's blind turn, any move or capture by the blind player that is interrupted because it captured something on the way instead moves the now capturing piece to the spot where the interrupting capture occurred.
    • ex. blind black queen tries to move 5 spaces, but a capture occurs at the 3rd space and stops the queen at the 3rd space.
  3. A player can "unknowingly but legally" put himself into check during his "blind" turn. This essentially gives each player a "get out of check free" ability only valid during their blind turn. This also means that if a king is checkmated or stalemated immediately before that king would go blind, that blind player gets an extra turn in which they can "unknowingly but legally" put himself into check. If a checkmate or stalemate is the case at start of that king's following turn, then it's a checkmate or stalemate as normal. In the blind player's next turn (which is always a turn where that player isn't blind) they must attempt to get out of check as usual.

I recommend signifying the end of your turn by advancing the "clock" (or whatever you're using to keep track of the current phase) as your opponent can't tell if you've removed your fingers from the piece when your fingers (and the peice) are hidden by the divider.

Note that more uncertainty is created by not capturing a piece when your opponent is blind than capturing a piece, as when you capture a piece when your opponent is blind they obviously know the location of the capturing piece (however, they don't know what the capturing piece is).

1 comment: