p.boxed
  | When a piece moves, the initial square disappears. It creates a 
  a(href="https://en.wikipedia.org/wiki/Wormhole") "wormhole"
  | .

p.
  Since all initial squares vanish, the board has exactly 64 - T squares
  after T turns, so the game cannot last more than 32 moves.
  Indeed a vanished square can be jumped over, but cannot be used again.
  Holes are indicated with the letter 'x' on FEN strings.

p.
  In the diagram situation, the black knight can go to all the marked squares:
  g5 and f6 are reachable because of the holes on f4 and e5.
  Indeed the knight first moves one square vertically or horizontally,
  and only then one square diagonally "in the same direction".
  This is the only valid description in this variant
  (others would lead to different knight movements around holes).
  The black king can go to c6:
  it moves to the closest non-vanished square (if any).

figure.diagram-container
  .diagram
    | fen:rbkxxxbn/ppxppppx/2qxxB2/4x2p/3P1x2/3n1x2/PPPxPPPP/RBxxxNKR b2,f2,b4,c5,g5,f6:
  figcaption Possible moves for the knight on d3.

p.
  No castle or en passant captures are possible.
  Promotion is permitted but only by capturing.

h3 Pieces movements

ul
  li The rook moves one or two squares vertically or horizontally.
  li The bishop moves one or two squares diagonally.
  li The queen moves either like a rook or like a bishop.
  li The other pieces move like in orthodox chess.
p All pieces can jump over others when moving by two squares.

h3 End of the game

p Win by checkmate or stalemate: if you can no longer move, you lose.

h3 Source

p
  a(href="https://www.chessvariants.com/32turn.dir/wormhole.html")
    | Wormhole chess
  |  on chessvariants.com.
  | I changed the pieces movements because I have a better feeling with the
  | moves described earlier. It might evolve.

p
  | Inventor (with other pieces' movements): Fergus Duniho (2000).
  | Similar to 
  a(href="https://www.chessvariants.com/boardrules.dir/cheshir.html")
    | Cheshire Cat Chess
  |  by Vernon R. Parton (1970).