Chess tactic

Tactics are usually contrasted with strategy, whereby the individual moves by themselves do not make indefensible threats, and the cumulative advantage of them takes longer to capitalise.

Examples of strategic advantages are weaknesses in, compromised pawn structure in, and sustained pressure on, the opponent's position.

Tactics usually follow one of a number of repeating patterns; these include forks, skewers, batteries, discovered attacks, undermining, overloading, deflection, pins, and interference.

At the professional level, often the mere threat of material loss (i.e., an anticipated tactic) induces the opponent to pursue an alternative line.

In amateur games, however, tactics often come to full fruition – unforeseen by the opponent and resulting in material gain and a corresponding, perhaps decisive, advantage.

A double check always forces the opponent to move the king, since it is impossible to defend against attacks from two directions in any other way.

A common situation is a knight played to c2 or c7, threatening both the enemy rook and king.

The opponent cannot choose to defend the other piece, or use a zwischenzug (other than a cross check) to complicate the situation.

Only bishops, rooks, and queens can perform a pin, since they can move more than one square in a straight line.

A single pawn typically forces a more powerful piece, such as a rook or a knight, to retreat.

Pawn sacrifices in the opening are known as gambits; they are usually not intended for material gain, but rather to achieve a more active position.

Situations involving zugzwang seldom occur before the endgame, where there are fewer choices of available moves.