A block is a defensive tactic in

chess Chess is a board game for two players. It is an abstract strategy game that involves Perfect information, no hidden information and no elements of game of chance, chance. It is played on a square chessboard, board consisting of 64 squares arran ...

in response to an attack, consisting of interposing a piece between the opponent's attacking piece and the piece being attacked. This type of blocking will only work if the attacking piece is a type that can move linearly an indefinite number of squares such as a

queen Queen most commonly refers to: * Queen regnant, a female monarch of a kingdom * Queen consort, the wife of a reigning king * Queen (band), a British rock band Queen or QUEEN may also refer to: Monarchy * Queen dowager, the widow of a king * Q ...

, rook, or

bishop A bishop is an ordained member of the clergy who is entrusted with a position of Episcopal polity, authority and oversight in a religious institution. In Christianity, bishops are normally responsible for the governance and administration of di ...

and there is at least one empty square in the line between the attacking and attacked piece. Blocking is not an option when the attacking piece is directly adjacent to the piece it is attacking, or when the attacking piece is a

knight A knight is a person granted an honorary title of a knighthood by a head of state (including the pope) or representative for service to the monarch, the church, or the country, especially in a military capacity. The concept of a knighthood ...

(because knights "jump over other pieces" and cannot be blocked). When an opponent's attack on a piece is blocked, the blocking piece is to some extent pinned, either relatively or absolutely, until a future move by either side allows it to be unpinned. A check on a

king King is a royal title given to a male monarch. A king is an Absolute monarchy, absolute monarch if he holds unrestricted Government, governmental power or exercises full sovereignty over a nation. Conversely, he is a Constitutional monarchy, ...

by an opponent's queen, rook, or bishop can sometimes be blocked by moving a piece to a square in line in between the opponent's checking piece and the checked king. The blocking piece is then absolutely pinned to the king by the attacking piece. Another type of interposing in chess can involve placing a piece between two opponent's pieces where one of those pieces is protecting the other, or they are both protecting each other. This chess tactic can be called ''

interference Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extra ...

''.

Blocking and initiative

When the attack cannot be ignored, the attacking player has the

initiative Popular initiative A popular initiative (also citizens' initiative) is a form of direct democracy by which a petition meeting certain hurdles can force a legal procedure on a proposition. In direct initiative, the proposition is put direct ...

. The defending player may be able to acquire the initiative by blocking and attacking at the same time, by attacking an undefended attacker with the blocking piece, with a

discovered attack In chess, a discovered attack is a direct attack revealed when one piece moves out of the way of another. Discovered attacks can be extremely powerful, as the piece moved can make a threat independently of the piece it reveals. Like many chess ...

, or when the block is also a check or a cross-check.

References

Chess tactics Chess terminology {{chess-stub

Blocking and initiative

See also

References