Pins, forks, x-rays, skewers and other tactical patterns.
Skewer
Attack on a valuable piece that, when it moves, exposes another.
Interference
Block the defensive line between two opposing pieces.
Deflection
Force a defender to abandon its protective role.
Attraction
Lure an opposing piece to an unfavorable square.
X-Ray Attack
Attack that goes through one piece to reach another behind it.
Fork
One piece attacks two or more targets at the same time.
Pin
Piece immobilized because it is protecting a more valuable one.
Discovered Attack
By moving one piece, another reveals its attack.
Removing the Defender
Capture or remove the piece protecting a target.
Discovered Check
By moving one piece, another delivers check to the king.
Positional Sacrifice
Give up material to gain long-lasting positional advantage.
Zugzwang
Position where any move worsens the situation.
Overloading
Exploit a piece that is defending too much at once.