bishop
Enable an AI agent to recognise a bishop chess piece, record its physical and game state, and determine its permitted use under the applicable chess rules.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an AI agent to recognise a bishop chess piece, record its physical and game state, and determine its permitted use under the applicable chess rules.
A bishop is a chess piece that moves any number of squares diagonally without jumping over intervening pieces and therefore remains on squares of one colour throughout play.
It can be Identify a bishop using set conventions, markings and declared role.; Enumerate unobstructed diagonal destinations and opposing pieces eligible for capture.; Filter candidate moves against the whole position's king-safety constraints.; Track light-square or dark-square reach and distinguish attacks from legal moves.; Place a bishop during setup or pawn promotion when permitted by the governing rules.; Flag an ambiguous or damaged bishop for clarification or replacement..
Distinguishing features
Under orthodox chess rules, moves diagonally through unobstructed squares; unlike a rook, it cannot move orthogonally.
Unlike a queen, combines no orthogonal movement with its diagonal movement.
Unlike a knight, cannot jump over intervening pieces.
Remains on the same square colour throughout ordinary movement, making light-squared and dark-squared bishops distinct operational categories.
Often has a split or notched head in Staunton-style sets, but assigned role and set conventions take precedence over shape alone.
Scope
+ Identification as a bishop and distinction from other chess-piece kinds
+ Side, square, diagonal movement and square-colour restriction
+ Bishop-specific capture eligibility and constraints on legal moves
+ Physical recognisability, condition and suitability for board use
+ Bishop provenance through initial setup, promotion or substitute designation
- Bishop as a religious office or the person holding it
- The complete chess ruleset and whole-game adjudication
- Chessboard construction and the complete chess-set inventory
- Other piece kinds except where needed to distinguish a bishop
- Comprehensive chess strategy, opening theory and game evaluation
Characteristics
- Assigned piece role
- bishop; uncertain designation Determines movement rights even when the physical token is unconventional or substituted.
- Playing side
- White or Black in orthodox chess Determines friendly occupancy, opposing pieces and whose turn permits movement.
- Current square
- a1-h8 on a standard board; off-board; unknown Anchors movement, capture and attack calculations.
- Square-colour class
- light-squared; dark-squared; unassigned Restricts the bishop's reachable squares during ordinary play.
- Participation state
- in play; captured; spare; awaiting promotion placement; unknown Separates active pieces from physically present tokens that cannot move.
- Diagonal occupancy
- ordered occupied and empty squares along each of four diagonal rays Determines movement reach and the first possible capture on each ray.
- Role origin
- initial setup; pawn promotion; composed position; unknown Explains bishops beyond the initial allocation without misclassifying the position.
- Physical dimensions
- height and base diameter in mm Supports assessment of board fit and distinction within the actual set.
- Physical recognisability and stability
- clear and stable; ambiguous; damaged; unstable; unassessed Determines whether players or agents can reliably identify and place the piece.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.bishop
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 17 findings · 27 questions.
Bishop identity Establishes the chess sense and the relationship between physical token and assigned bishop role.
The name is ambiguous, and bishop appearance varies across chess sets.
Registered sense
Bounds the entry to the chess-piece concept.
Chess sense boundary
The draft adopts the chess-piece interpretation; source verification must establish that this matches the registry identifier.
- Does the source record behind vr.tr.bishop-q134 explicitly identify the chess piece? provenance
- Does this registry entry own only the physical piece kind, or also its abstract role in digital chess? boundary
Token and role
Separates recognition by form from authoritative assignment in play.
Bishop designation
A familiar notched head supports recognition, but unconventional sets and substitutes require contextual identification.
- Which shape, symbol or marking identifies bishops in this particular set? definition
- If the token is a substitute, what declaration or governing procedure establishes its bishop role? provenance
Diagonal reach Captures the bishop's movement geometry and occupancy constraints.
Diagonal sliding and square-colour confinement are the bishop's defining operational properties.
Movement geometry
Locates the bishop and derives its diagonal rays.
Colour-bound diagonals
In orthodox chess, a bishop moves along diagonals and retains its square-colour class.
- What is the bishop's current square and resulting light-square or dark-square class? measurement
- Which destinations lie on a nonzero diagonal from that square within the board boundary? measurement
Blocking and capture
Limits geometric reach using the first occupied square on each diagonal.
First-occupant limit
A bishop cannot cross an occupied square; a first opposing occupant is a candidate capture, while a friendly occupant prevents landing.
- Which piece is the first occupant on each diagonal ray, and which side owns it? measurement
- Which empty destinations and first opposing occupants remain candidate moves or captures? action
Position-dependent permission Connects bishop movement to turn ownership, king safety and attack semantics.
Diagonal reach alone cannot establish whether a bishop move is legal or how the bishop affects a king.
Legal move filter
Applies whole-position constraints to bishop move candidates.
King-safety dependency
An otherwise reachable destination is illegal if the move leaves the moving side's king in check.
- Is the bishop active and owned by the side whose turn it is? action
- After each candidate move, would its own king remain or become attacked, including through a diagonal or other line the bishop vacates? action
Attacks and defence
Distinguishes attacked squares from legal movement and friendly-piece defence.
Attack versus move
Under orthodox rules, restriction by king safety does not erase a bishop's attacks; friendly occupied endpoints also require separate defence interpretation.
- Which squares does this bishop attack under the governing rules, including when it is pinned to its king? definition
- Which friendly pieces occupy its first diagonal endpoints and are therefore defended along those lines? measurement
Bishop entry and material use Records how a bishop enters a position and whether its physical representation is usable.
Promotions alter bishop counts, while physical ambiguity can prevent reliable execution of otherwise valid chess actions.
Setup and promotion
Tracks initial allocation, promoted bishops and transitions out of play.
Bishop role origin
Orthodox initial setup supplies two bishops per side on opposite square colours; promotion can create additional bishops, including multiple bishops on one colour.
- Did this bishop enter through initial setup, pawn promotion or an explicitly supplied position? provenance
- What square and side establish a promoted bishop's square-colour class? measurement
- Which recorded capture or placement event changed this bishop's participation state? provenance
Physical playability
Assesses the token's bishop-specific recognisability and compatibility with the playing set.
Usable bishop token
The token must remain distinguishable as a bishop of the correct side and occupy its square without avoidable placement ambiguity.
- Can this token be reliably distinguished from the set's pawns, queen and king despite wear, damage or stylisation? measurement
- Do its base diameter, height and stability suit the board and applicable equipment requirements? measurement
- What permitted replacement or designation procedure applies if a bishop token is unavailable or ambiguous? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The chess-piece sense is inferred from PHY.OBJ; the registry provides no recorded sense.
- Movement and counts refer to standard chess on an 8×8 board; variants may differ.
- These are recalled facts, not researched findings; current equipment specifications and physical dimensions require verification.
- Which of these check these first hold for the sense of bishop this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Light-squared bishop
- Dark-squared bishop
- Which of these kinds and varieties hold for the sense of bishop this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- English algebraic chess notation - B - Identifies the piece type in moves such as Be3; notation letters vary by language.
- Forsyth-Edwards Notation (FEN) - B / b - Uppercase denotes a White bishop; lowercase denotes a Black bishop.
- Unicode - U+2657 / U+265D - WHITE CHESS BISHOP and BLACK CHESS BISHOP symbols.
- Which of these identifiers and schemes hold for the sense of bishop this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- FIDE Laws of Chess: the International Chess Federation specifies bishop movement, capture and initial placement.
- Which of these standards and regulation hold for the sense of bishop this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Each player begins standard chess with two bishops, one on each square colour.
- Controls diagonal lines for attacks, defence and restriction of opposing pieces.
- A pawn reaching its promotion rank may be promoted to a bishop.
- Which of these real-world use hold for the sense of bishop this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Starting number per player - 2 - pieces
- Distance travelled in one legal move on a standard board - 1-7 - diagonal square steps
- Squares reachable across successive moves on an otherwise empty standard board - 32 - squares
- Which of these typical measurements hold for the sense of bishop this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Small physical pieces can present a choking hazard to young children.
- Poorly differentiated piece shapes can cause confusion with other chessmen.
- A chipped base or loose weighting can make a physical piece unstable.
- Which of these failure modes and hazards hold for the sense of bishop this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- The equivalent piece has different names across languages, including French fou, German Läufer and Russian slon.
- Physical designs vary across chess-set traditions; Staunton-style bishops commonly have a slotted, mitre-like head.
- Which of these regional variation hold for the sense of bishop this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- rook - A rook moves along ranks and files; a bishop moves diagonally.
- queen - A queen combines rook and bishop movement; a bishop has only diagonal movement.
- knight - A knight moves in an L-shaped pattern and can jump over intervening pieces.
- bishop (religious office) - An ecclesiastical bishop is a religious officeholder; this entry describes a chess piece.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of bishop this model covers, and on what evidence? provenance
What the second pass must settle
- Verify that the registry identifier denotes the chess bishop and determine whether an existing Vercy model already owns this concept.
- Identify and read the authoritative chess rules edition supporting movement, attack semantics, promotion and substitute-piece procedures.
- Settle whether the model covers only orthodox chess or explicitly includes variants with different boards, setup or bishop movement.
- Determine which equipment standards and recognition conventions apply across competition, decorative and accessible chess sets.
- Settle the ownership boundary between the physical bishop token, its abstract game role and a bishop represented only in software.