Positions Only (PCN v1.0.0)

This page collects FEEN-only documents—no moves—for puzzles, endgame studies, opening snapshots, teaching positions, or cross-style setups.

Minimum valid PCN requires only setup (FEEN). You may still include meta and sides for context; omit moves and status if not needed.

1) Absolute Minimum (Empty Board)

{
  "setup": "8/8/8/8/8/8/8/8 / U/u"
}

Use case: neutral canvas for editors, coordinate testing, or CELL integration checks.

2) Chess Puzzle — “Mate in One”

{
  "meta": { "name": "Mate in One" },
  "setup": "+r1bq+kb1+r/+p+p+p+p1+p+p+p/2n2n2/4p2Q/2B1P3/8/+P+P+P+P1+P+P+P/+RNB1+K1N+R / C/c"
}

Notes: status omitted intentionally—viewers or solvers can infer/verify the objective.

3) Endgame Study — K+P vs K

{
  "meta": { "name": "King and Pawn Study" },
  "setup": "8/8/8/8/4k3/8/4P3/4K3 / C/c"
}

Tip: Perfect for engines or lessons that demonstrate technique from a fixed position.

4) Opening Snapshot — Italian Game Start

{
  "meta": { "name": "Italian Game — Start Position" },
  "setup": "+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 / C/c"
}

Use case: save a named opening position without committing to a line.

5) Shōgi Position — Midgame Diagram

{
  "meta": { "event": "Training Diagram" },
  "sides": {
    "first":  { "style": "SHOGI" },
    "second": { "style": "shogi" }
  },
  "setup": "lnsgkgsnl/1r5b1/pppp1pppp/5p3/9/2P6/PP1PPPPPP/1B5R1/LNSGKGSNL / S/s"
}

Note: sides declares styles for clarity; no moves are recorded.

6) Cross-Style Setup — Chess vs Makruk

{
  "sides": {
    "first":  { "style": "CHESS",  "name": "Western" },
    "second": { "style": "makruk", "name": "Thai" }
  },
  "setup": "rnsmksnr/8/pppppppp/8/8/8/+P+P+P+P+P+P+P+P/+RNBQ+KBN+R / C/m"
}

Purpose: frozen snapshot for rule comparison or cross-variant teaching.

7) Thematic Puzzle — En Passant Ready

{
  "meta": { "name": "En Passant Theme" },
  "setup": "+rnbq+kbn+r/+p+p+p1+p1+p+p/8/3pP-p2/8/8/+P+P+P+P1+P+P+P/+RNBQ+KBN+R / C/c"
}

Hint: A viewer can propose candidate moves or ask solvers to find the idea.

8) Piece-in-Hand (Drops) — Shōgi Reserve Focus

{
  "meta": { "name": "Drop Resource Position" },
  "sides": {
    "first":  { "style": "SHOGI" },
    "second": { "style": "shogi" }
  },
  "setup": "lnsgkg1nl/1r5s1/pppppp1pp/6p2/9/2P6/PP1PPPPPP/7R1/LNSGKGSNL B/b S/s"
}

Note: FEEN reserve sections let you encode pieces in hand—ideal for drop puzzles.

9) Neutral Board — Teaching Grid

{
  "meta": { "name": "Teaching Grid" },
  "setup": "8/8/8/8/8/8/8/8 / U/u"
}

Use case: overlay arrows/highlights in a UI (outside PCN core) without any moves.

10) Status-Ready but Unspecified

{
  "meta": { "name": "Stalemate Candidate" },
  "setup": "7k/5Q2/6K1/8/8/8/8/8 / c/C"
}

Comment: Final status like "stalemate" could be added, but leaving it out enables solvers to evaluate the position.

Tips for Position-Only Documents

Required: setup (FEEN). Everything else optional.
No time control: Omit sides.{first|second}.periods or set them to [].
Cross-style clarity: Add sides.first.style / sides.second.style to clarify intended rules, especially for puzzles that depend on style legality.
Reproducibility: Use meta.name, meta.event, or meta.href to tag sources.
From position to play: You can later append a moves array to continue from the same FEEN without changing IDs.

For end-to-end examples, see Complete Game Records. For timing-focused examples, visit Time Control Systems. For special actions (castling, drops, promotion), check Special Moves.