Technology, online play, and variants
Engines, platforms, composition, stable slang, and recognized variants.
129 terms
Computer chess and analysis
33- Chess engineA program that analyzes a position, compares legal move sequences, and recommends options based on its calculations.
- Graphical User InterfaceA visual application that lets users control chess software through a board, controls, and panels instead of text commands.
- Local engineA chess-analysis program that runs on the user's own device and uses that machine's processor and memory.
- Cloud engineA chess-analysis program that performs its calculations on a remote computer and returns the results over a network.
- Principal variationThe move sequence a chess-analysis program currently considers the best continuation for both sides from a position.
- DepthAn indicator of how far a chess engine's current search has progressed from the position being analyzed.
- Nodes per secondA measure of how many positions a chess engine processes per second during search.
- Transposition tableMemory that lets a chess engine reuse results for positions it has already searched.
- Opening bookA database of opening positions and moves that a chess program can consult before normal search.
- TablebaseA precomputed database that gives exact results for endgames within a limited number of pieces.
- NNUEA neural-network architecture designed to evaluate chess positions while updating efficiently between nearby positions.
- Alpha-beta pruningA method that skips branches unable to change the final choice when both sides seek their best result.Advanced
- BitboardA representation with 64 zero-or-one indicators, one per square, marking which squares belong to a chosen set.Intermediate
- Depth to ConversionA precomputed endgame metric measuring the distance to a capture or promotion, or to mate if it comes first.Expert
- Distance to mateA metric counting the distance to forced mate when the winner hastens it and the defender delays it.Advanced
- Distance to zeroA precomputed endgame metric measuring the distance to mate or to the next move that resets the fifty-move counter.Advanced
- Endgame bitbaseA compact precomputed structure that stores minimal outcome information for many endgame positions.Advanced
- Evaluation functionA procedure that assigns a numerical estimate to a position so a chess program can guide its search.Intermediate
- Horizon effectAn error caused when a decisive consequence lies just beyond the search limit and distorts the evaluation.Intermediate
- Iterative deepeningA strategy that repeats search with increasing limits so a completed result is always available.Advanced
- Late move reductionsA technique that initially searches moves placed late in a position's analysis order at reduced depth.Advanced
- MinimaxAn algorithm that chooses a move while assuming both sides will always make their best available decisions.Intermediate
- Monte Carlo tree searchA method that repeatedly explores variations and spends more analysis on moves that appear promising.Advanced
- Move orderingA technique that chooses which moves to search first so unhelpful branches can be rejected sooner.Advanced
- MultiPVAn analysis mode that displays several candidate moves with a line and evaluation for each one.Intermediate
- Null-move pruningA heuristic that tests a fictional pass to discard positions that appear clearly sufficient.Advanced
- PerftA test that counts every legal move sequence to an exact search depth.Intermediate
- PonderingA mode in which an engine searches while the opponent's clock runs, usually from a predicted reply.Intermediate
- Principal variation searchAn optimization that fully searches the first candidate and initially tests later moves with a narrower check.Advanced
- Quiescence searchAn extension that continues selected tactical moves until the position is stable enough to evaluate.Advanced
- Static exchange evaluationA fast calculation that estimates the material balance of successive captures and recaptures on one square.Advanced
- Win/Draw/Loss tablebase valueThe exact win, draw, or loss outcome that a tablebase assigns to an endgame position.Advanced
- Zobrist hashingA method that creates a quickly updatable numerical fingerprint for the complete state of a chess position.Advanced
Online chess and stable slang
16- PremoveAn online chess feature that queues a move during the opponent's turn for automatic execution afterward.
- FlaggingMaking the opponent run out of time, usually to win although some positions are drawn.
- BerserkA Lichess Arena option that voluntarily cuts a player's time in exchange for an extra tournament point after a qualifying win.
- Mouse slipAn online-chess input error that causes a different legal move from the one the player intended to enter.
- SandbaggingDeliberately playing below one's true strength to make a displayed rating or competitive level artificially low.
- BoostingArtificially inflating an account's competitive rating or results through arranged outcomes or other non-competitive behavior.
- SmurfingUsing an account that presents a strong player as far weaker than the player really is.
- Account sharingMore than one person using the same chess account, especially when someone plays games on behalf of the account holder.
- Auto-queenA setting that automatically turns a pawn reaching the last rank into a queen.Basic
- Conditional moveA preprogrammed reply that executes only when the opponent makes the exact predicted move.Intermediate
- DisconnectionAn interruption of the link between a player's authorized device and the platform hosting the game.Basic
- LagDelay between a player's action and its arrival at the server or the return of the response.Basic
- Lag compensationA mechanism that partially adjusts the clock for network delay measured by the platform.Intermediate
- Move confirmationA setting that requires approval of a selected move before it is submitted to the online board.Basic
- Playing zoneThe digital environment that hosts the board, clock, and controls needed to play an online chess game.Basic
- TakebackA feature that restores an earlier position by withdrawing a move that the game has already accepted.Basic
Fair play and cheating terminology
15- Engine assistanceUsing a chess engine for evaluations, moves, or analysis during a game in which that help is prohibited.
- Anti-cheatingRules, controls, and investigative methods designed to prevent and detect prohibited assistance or competitive manipulation.
- CollusionIntentional cooperation between participants to deceive others, obtain improper help, or manipulate a competition.
- Assumed cheatingA regulatory presumption triggered when an approved statistical analysis exceeds the official threshold for a performance.Advanced
- CheatingThe deliberate use of prohibited help or competition manipulation to obtain an improper advantage.Basic
- Competition manipulationAn intentional and improper alteration of a competition's result or course in order to obtain an advantage.Intermediate
- External assistanceInformation or advice from outside the player's own thinking that is used during a game.Basic
- Fair playThe principle of competing honestly, following the rules, and letting results depend on the players' genuine play.Basic
- Fair Play softwareA tool that examines games and competition data to identify integrity patterns that may warrant review.Intermediate
- False identityCompetitive participation under an identity that does not belong to the person actually playing or recorded as the player.Intermediate
- Fictitious tournament or gameA tournament or game entered in competitive records as real even though it did not genuinely occur as represented.Intermediate
- Match-fixingAn improper agreement or plan to predetermine the result of a game or competition.Intermediate
- Online technical rule violationA breach of an online event's technical or supervision requirements that can be penalized without itself implying cheating.Intermediate
- Rating fraudThe deliberate distortion of results, identities, or records to create or exploit a rating that misrepresents genuine competition.Intermediate
- Reckless or manifestly unfounded cheating accusationA cheating allegation made without acceptable grounds that could give a reasonable person a genuine suspicion.Advanced
Chess composition and studies
42- Chess compositionThe deliberate creation of a chess position or task designed to express an idea through a defined solution.
- Chess problemA deliberately constructed position that sets a precise task and has a solution intended by its composer.
- Endgame studyA composition in which White must force a win or draw from a position created by the composer.
- DirectmateA problem in which White moves first and forces mate against every Black defense within the stated number of moves.
- TwomoverA directmate in which White must force checkmate in no more than two White moves.
- ThreemoverA directmate in which White must force checkmate in no more than three White moves.
- MoremoverA directmate problem in which White must force mate in four or more White moves.
- HelpmateA problem in which Black and White cooperate so that White checkmates the black king in the stated number of moves.
- SelfmateA problem in which White forces a resisting Black to checkmate the white king.
- Retrograde analysisBackward reasoning that deduces which earlier moves or events are compatible with the current position and legal chess play.
- Proof gameA legal sequence from the initial chess position to a given position, showing that the target position can be reached.
- Fairy chessChess composition that introduces pieces, conditions, boards, or other rules that differ from orthodox chess.
- CookAn unintended solution that begins with a different first move from the author's solution and makes the composition unsound.
- Set playVirtual play already prepared in the initial position before the actual first move of the solution.
- TryA nearly correct first move that fails to exactly one Black defense, called the refutation.
- KeyThe correct first move that begins the actual solution of a problem, especially a directmate.
- Model mateA compositional checkmate combining purity around the mated king with economical participation by the mating side's pieces.
- NovotnyA composition theme where a White piece occupies the intersection of two Black defensive lines and forces interference between them.
- GrimshawA composition theme where two same-colored pieces mutually block one another by occupying the same intersection square in separate variations.
- AnticipationThe situation in which an identical chess composition already has an earlier priority date.Advanced
- Babson taskA composition theme in which every Black promotion is answered by a White promotion to the same piece.
- Block problemA composition in which White's first move creates no threat and every Black move permits a prepared White response.Intermediate
- Bristol clearanceA theme in which one piece moves ahead along a row, column, or diagonal so a same-color piece can follow on that line.
- CirceAn added chess rule in which a captured piece is immediately reborn on a designated home square.
- DualA situation in which more than one continuation satisfies the composition's task after the first move.Intermediate
- Dual avoidanceA theme in which several continuations appear possible, but after each defense exactly one works and the others are excluded.Advanced
- ExcelsiorA theme in which a pawn starts on its original row, crosses the board, and promotes, meaning it becomes another piece.
- GrasshopperA nonstandard chess piece that hurdles another piece on a row, column, or diagonal and lands exactly one square beyond it.Intermediate
- Half-pinA mechanism in which two Black pieces screen their king on one line and either one's departure prevents the other from moving away.Advanced
- Lačny themeA theme in which the same Black defenses receive White mating replies that rotate cyclically between two or more parts of the solution.
- MaximummerAn added rule that normally requires Black to choose a legal move with the greatest straight-line distance from start to finish.Advanced
- MeredithA composition whose initial diagram contains eight to twelve units, counting every king, queen, rook, bishop, knight, and pawn.
- MiniatureA composition whose initial diagram contains at most seven units, counting kings, queens, rooks, bishops, knights, and pawns.Basic
- NightriderA nonstandard chess piece that repeats one or more knight steps in the same direction as a single move.Intermediate
- Partial Retrograde AnalysisA convention that splits a solution into parts when permissions for certain special moves depend on incompatible legal histories.Expert
- PlachuttaA theme in which a sacrifice at two crossing defensive lines makes either capturing piece obstruct the other.
- ReflexmateA problem in which White forces Black to mate White and either side must mate immediately whenever possible.Advanced
- SeriesmoverA family of problems in which one side makes several consecutive moves while the other side remains stationary.Advanced
- SoundnessThe property that a chess composition has exactly its intended solution and no defect that invalidates it.Intermediate
- StipulationThe exact task a chess composition requires, together with any conditions needed to interpret that task.Basic
- Virtual playThematic play contained in hypothetical possibilities of a composition even though it is not the line ultimately carried out.Intermediate
- Zagoruiko themeA theme in which the same two or more Black defenses receive different White mates across at least three phases of a problem.
Variants and social formats
23- Chess960A chess variant with 960 legal back-rank starting arrangements and adapted castling rules.
- BughouseA four-player team variant on two boards where captured pieces are passed to a partner and can be dropped back into play.
- CrazyhouseA two-player variant where captured pieces change sides, enter a reserve, and can later be dropped back onto the board.
- Atomic chessA variant where every capture causes an explosion that removes the captured piece, the capturer, and nearby pieces under special rules.
- Three-checkA variant that keeps normal chess rules and adds an immediate win for delivering a third legal check to the opposing king.
- King of the HillA variant that keeps normal chess rules and lets a player win by legally moving their king onto one of the four central squares.
- HordeAn asymmetric variant where one side controls a large pawn horde without a king while the other keeps a normal chess army.
- Racing KingsA pawnless variant with a special starting position where the goal is to race your king to the eighth rank without giving check.
- AntichessA reversed-objective variant where captures are compulsory and you normally win by losing all your pieces or having no legal move.
- Odds chessA chess format where an agreed starting advantage is used to compensate for a difference in playing strength.
- Advanced chessA format in which an authorized player combines personal judgment with analysis software and searchable game collections during play.
- Alice chessA two-board variant in which every moving piece transfers to the opposite board after completing its move.
- Capablanca chessA 10-by-8 variant adding one piece that combines bishop and knight movement and another that combines rook and knight movement.
- ChessboxingA hybrid sport in which two competitors alternate rounds of one continuing chess game and one continuing boxing bout.
- Duck chessA variant in which every turn combines a chess move with the mandatory placement of a shared blocking duck.
- Fog of War chessA hidden-information variant in which each player sees only their pieces and the squares those pieces can legally reach.
- Four-player chessA family of variants in which four armies take turns in one game on a shared four-sided board.
- Gliński's hexagonal chessWładysław Gliński's variant played on a three-colored hexagonal board containing 91 cells.
- Grand ChessChristian Freeling's 10-by-10 variant with two pieces combining familiar movements and pawns that promote by restoring captured friendly pieces.
- KriegspielA hidden-information variant in which a referee validates attempted moves and communicates only limited facts.
- Marseillais chessA variant in which each normal turn gives the same player two consecutive moves.
- Progressive chessA family of variants in which each turn contains one more move than the preceding turn.
- Seirawan chessA standard-board variant that adds a hawk and elephant from reserve when an original piece vacates its starting square.