From GameBrew

Last Updated2008/04/09

ChessNET is the first homebrew chess game for the DS to feature online play (and more than one player). It allows you to play chess online in a play-by-mail style, whereas each time you make a move, the information is sent back to the server and stored (for days) until your opponent loads up their game, receives the data, and makes their move. It continues in this ping pong fashion until the game ends.

There is also a local single-DS mode, where you and an opponent can just hand off the device between moves.

It was an entry of the NEO Spring Coding Comp 2008.


Download and extract file.

DLDI patch it and copy it to the root directory of the card.

Note: Make sure to configure WFC data to get online play working.

User guide

Local play

For local play, 2 players may share a DS to play a hotseat game of chess. Multiple game slots allow for up to 10 games to be saved at once, and the DS will automatically save after every move - In case of power loss or other trouble.

Online play

ChessNET is designed in play-by-mail style. So instead of real-time online games, there's a long time for players to make their moves. Days, even. This allows for players to make well formulated and studied moves. In addition, you don't have to wait on the one game.

It supports up to 128 online games at once (Since none of the data is recorded to the DS, but instead to an online server).

All game data is written to _ChessNET.sav on your cards root. On it's first connection to the server (if play online) it will request and store a unique ID for your DS. If you delete _ChessNET.sav, you will essentially lose your account. Make sure to keep a copy if you plan on trashing the file.


Use D-pad and buttons or by stylus to activate functions or movements on the board.


Works on M3 Real (firmware 4.2e).



  • Added a custom icon to the ROM.
  • Added account handles and passwords.
  • Added account registration.
  • Added support for Castling.
  • Added support for En Passant.
  • Added support for 50 Move Rule.
  • Added status screen while the DS downloads a game.
  • Fixed a buffering error in the Client POST Handler.
  • Fixed checkmate detection [No more victory on check].
  • Completed the About menu option.
  • Local save games show when the last move occured.
  • Added screens after winning or losing a match.
  • Touched up the Online Games screen.
  • Touched up the Find Opponent screen.

External links