Fork
One piece attacks two or more valuable targets at once.
Chess concepts
Understand the idea. Step through an example. Try it yourself.
35 concepts
Pin
Moving a piece would expose its king or a more valuable piece behind it.
Skewer
An attack on a valuable piece forces it away, exposing a piece behind it.
Deflection
A defender is forced away from the square or piece it protects.
Attraction
A piece is drawn onto a square where a follow-up tactic works.
Clearance
A move frees a square or opens a line for another piece.
Interference
A piece is placed between an enemy defender and its target.
Discovered attack
Moving one piece uncovers an attack by another piece.
Overloaded defender
One defender has more defensive jobs than it can perform after a forcing move.
Double attack
One move creates two threats that cannot both be answered.
Decoy
A piece is tempted or forced onto an unfavorable square.
Desperado
A piece that is likely to be lost gains something before it disappears.
Windmill
Repeated discovered checks let a piece collect material between checks.
Exchange sacrifice
A rook is given for a bishop or knight in return for another benefit.
Mating net
Pieces work together to restrict the king and prepare checkmate.
Perpetual check
Repeated checks can prevent an opponent from escaping a drawn repetition.
Stalemate resource
A losing side can sometimes force a position with no legal moves while its king is not in check.
Weak back rank
A king has limited escape squares behind its own pawns and is vulnerable to a rook or queen.
Line tactic
A rook, bishop, or queen uses a file, rank, or diagonal for a tactical threat.
Remove the defender
Capturing or displacing a defender makes another target vulnerable.
Tactics
Forcing moves produce a concrete result such as winning material or delivering mate.
Calculation
Work out a sequence of moves and the opponent’s strongest replies before moving.
King safety
A king needs protection from checks and coordinated attacks.
Defense
Find moves that meet an opponent’s threat or reduce its impact.
Development
Bring pieces from their starting squares into useful play.
Strategy
Choose a longer-term plan based on the position’s strengths and weaknesses.
Endgame technique
Use accurate king, pawn, and piece play when material is reduced.
Check
The king is attacked and the next move must remove that attack.
Checkmate
The king is attacked and there is no legal way to remove the attack.
Stalemate
The player to move has no legal move and is not in check; the game is drawn.
Hanging piece
A piece can be captured without sufficient compensation or an effective recapture.
Initiative
Your threats make the opponent respond while you direct the play.
Tempo
A unit of time in chess: one move. A threat can make an opponent spend a move responding.
Opposition
Kings face each other with an odd number of squares between them; the move can determine who gives way.
Passed pawn
No opposing pawn remains on its file or adjacent files ahead of it to stop its advance.