Terms used throughout blunder.ninja are linked straight to this glossary. Click any linked term on any page to jump to its definition here.
bishop pair
Having both bishops while the opponent has lost at least one. In open positions, the bishop pair is a powerful long-term advantage.
castle
A special king move where the king moves two squares toward a rook and the rook jumps over it. Castling kingside is usually safer.
counterplay
Active play by the defending side to create threats of their own instead of passively responding.
discovered attack
An attack created when one piece moves out of the way, revealing an attacking line from a piece behind it. A discovered check is especially dangerous.
doubled pawns
Two pawns of the same colour on the same file. They are a potential weakness because they cannot defend each other.
en passant
French for "in passing." When a pawn moves two squares forward, an enemy pawn can capture it as if it moved only one square.
endgame
The stage of the game when few pieces remain. Small advantages like an extra pawn or better king position become decisive.
fianchetto
Developing a bishop to b2/g2 or b7/g7, placing it on the longest diagonal for maximum influence. A hallmark of hypermodern openings.
fork
A single piece attacking two or more enemy pieces at once. Knights are especially good at forks.
gambit
A voluntary pawn sacrifice in the opening to gain rapid development, central control, or attacking chances. Accepted gambits require precise defence from the opponent.
hypermodern
A school of chess that advocates controlling the centre with pieces from a distance rather than occupying it with pawns early on.
isolated pawn
A pawn with no friendly pawns on adjacent files. It can be a weakness but also provides open lines for pieces.
open file
A file with no pawns of either colour. Rooks become very powerful on open files.
outpost
A square protected by one of your pawns that cannot be attacked by an enemy pawn. Knights on outposts are especially powerful.
passed pawn
A pawn with no opposing pawn blocking its path to promotion. Passed pawns become more dangerous in the endgame.
piece activity
How actively your pieces participate in the game. Active pieces control more squares and create threats.
pin
A pin is when a piece cannot move without exposing a more valuable piece behind it. For example, a bishop pins a knight to the king, forcing the knight to stay put.
promotion
When a pawn reaches the eighth rank, it must be exchanged for a queen, rook, bishop, or knight of the same colour.
prophylaxis
A move that prevents the opponent's plans rather than advancing your own. A mark of advanced positional play.
sacrifice
Giving up material deliberately in exchange for a positional advantage or attacking opportunity. Unlike a blunder, a sacrifice is calculated.
skewer
Like a pin in reverse - a valuable piece is attacked and must move, exposing a less valuable piece behind it.
tempo
A unit of time in chess, measured in moves. Gaining a tempo means making a move that forces the opponent to waste a move responding to a threat instead of pursuing their own plan.
transposition
Reaching the same position through a different move order. Knowing transpositions helps you avoid your opponent's prepared lines while still reaching familiar territory.
zugzwang
A German word for "compulsion to move." A player is in zugzwang when any legal move worsens their position.