First you need to select a piece to move.
Press a key from '1' to '8' to select your x coordinate.
Then press the 'enter' key to finalize your choice.
Do the same for the letters coordinates, 'a' through 'h'.
Once your piece is selected, it will turn red.
To move the piece, simply enter the coordinates for the square that you want your selected piece to move to, using the same method as described above.
Please note that there are few limitations*, as it is possible to move one of your pawns to defeat your opponent's king in the first turn.
Because of this, I kindly ask you to abide by the official rules of chess when playing a real game with someone.
Castling is sadly not an option yet, but you can work around it by moving either your castle or king to one space. Then make sure the other player selects one of his pieces, and then chooses the space he is already on. This will move his piece onto itself, thus letting you complete the two moves required for castling.
This game does not detect checkmate, so it ends when one of the two kings is captured.
*I should maybe say unlimitations.
I would appreciate any questions or general feedback at firstname.lastname@example.org.