Lichess Tatics

Fork (Double Attack).
A fork occurs when a single piece attacks two or more enemy pieces at the same time. Knights are particularly good at forks because of their unique movement pattern, but other pieces like queens and bishops can also execute forks.
For example:

• If a knight moves to a square where it attacks both the opponent's king and queen, the opponent must move the king, allowing the knight to capture the queen.

• A queen can fork a king and a rook, forcing the opponent into a tough position.

• 1. Pins
  A pin occurs when a piece is attacked and cannot move without exposing a more valuable piece behind it. There are two types:

  • Absolute Pin: The pinned piece cannot legally move because it would expose the king.
  • Relative Pin: The pinned piece can move, but doing so would result in losing a more valuable piece.

  Example: A bishop on g5 pinning a knight on f6 to the queen on d8.
  2. Skewers
  A skewer is similar to a pin but reversed—the more valuable piece is attacked first, forcing it to move and exposing a weaker piece behind it.
  Example: A rook attacking a king on e1 with a queen behind it on d1. The king must move, allowing the rook to capture the queen.
  3. Discovered Attacks
  A discovered attack happens when a piece moves, revealing an attack by another piece. If the revealed attack is a check, it's called a discovered check.
  Example: A bishop moves out of the way, uncovering an attack by a rook on the opponent’s queen.
  4. Double Attack
  A double attack occurs when a single move creates two threats at once. Knights are particularly good at this.
  Example: A knight moves to f7, attacking both the king and queen simultaneously.