Frequently Asked Questions
Common questions about Sashité specifications and their implementation.
General Questions
What is the difference between FEEN and FEN?
FEEN (Forsyth-Edwards Enhanced Notation) is an extension of the traditional FEN format with several key enhancements:
- Multi-dimensional support: FEEN can represent 3D chess and higher-dimensional games
- Cross-style games: Supports hybrid games where different players use different piece systems (e.g., Chess vs Shōgi)
- Captured pieces: Native support for pieces in hand/reserve (essential for Shōgi-style games)
- Enhanced piece states: Support for promoted pieces, castling eligibility, en passant vulnerability through state modifiers
Traditional FEN is limited to:
- 2D boards only
- Single game system (Western Chess)
- No captured piece representation
- Basic piece state support
Example comparison:
# Traditional FEN (Western Chess only)
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
# FEEN (same position, but extensible)
+rnbq+kbn+r/+p+p+p+p+p+p+p+p/8/8/8/8/+P+P+P+P+P+P+P+P/+RNBQ+KBN+R / CHESS/chess
# FEEN (Cross-style: Chess vs Makruk)
rnsmksnr/8/pppppppp/8/8/8/+P+P+P+P+P+P+P+P/+RNBQ+KBN+R / CHESS/makruk
# FEEN (With captured pieces - Shōgi style)
lnsgkgsnl/1r5b1/ppppppppp/9/9/2P6/PP1PPPPPP/1B5R1/LNSGKGSNL B/ shogi/SHOGI
Implementation Questions
More questions will be added based on community feedback and common implementation challenges.