Chess forks, pins and skewers: check the threat before moving

Start with the targets

Before naming a tactic, locate both kings and the pieces that are undefended. Ask which attacks already exist and which squares your pieces can reach legally. A recognisable pattern is only a candidate: a move that exposes your king cannot be played. Keep the board still while you inspect the threats rather than dragging a promising piece immediately.

A fork attacks two targets

A fork creates two or more threats with one piece. Knights are familiar examples, and other pieces can make the same double attack. Identify both targets, then ask whether the opponent can capture the attacking piece, answer both threats with one move or create a stronger threat. Attacking a king and another piece often restricts the reply because the check must be answered.

A pin makes moving costly or illegal

A pin restricts a piece standing between an attacker and a target behind it. If moving that piece would expose its king to check, the move is illegal: this is an absolute pin. If the piece behind is a queen or rook, moving may be legal but costly. Do not assume every restricted piece is helpless; inspect captures along the line and ways to block the attack.

A skewer reverses the order

In a skewer, the more valuable target is in front, with another target behind it along a line. Moving the front piece can reveal the second. Trace the full rank, file or diagonal, including intervening pieces. Then check whether the front piece can move with a counterattack, or whether the piece behind can be defended after the reply.

Calculate the defence, not just the label

After finding a candidate, mentally play the opponent’s strongest response. Can they capture your attacker, give check, block a line or move an attacked piece while creating a threat? Continue until the claimed gain survives. A fork that loses its attacking piece before either target can be taken is not a win merely because two pieces were attacked.

Review one missed condition

Write a specific note: “I saw the fork, but did not notice that the opponent could capture my knight.” Revisit a similar theme without a timer and explain the defence before committing. This guide is written by the publisher of Chess Puzzles, whose described features include theme practice and mistake review. Its release is pending; puzzle ratings do not guarantee improvement in tournament chess.

Further reading

• Lichess: fundamental tactics practice
• Chess Puzzles: publisher feature description