Strategy and tactics are the two complementary halves of chess thinking. Strategy refers to long-term planning around piece placement, pawn structure, and positional goals, while tactics are immediate concrete sequences that win material or deliver checkmate. Positional play emphasizes maneuvering for lasting advantages such as better pawn structure, active pieces, or control of key squares, whereas dynamic play seizes temporary opportunities, often through tactics and initiative. Piece values provide a baseline for evaluation: pawn 1, knight 3, bishop 3, rook 5, and queen 9, with the king considered invaluable. Material balance is the relative count of pieces on each side, and "winning a piece" means capturing a piece for less than its full value, while "winning the exchange" means trading a minor piece for a rook.
Tactics revolve around a set of recurring motifs. A pin attacks a piece that cannot move without exposing a more valuable piece behind it; an absolute pin is against the king and binds the pinned piece, while a relative pin is against a higher-value piece and is movable at a cost. A skewer forces a valuable piece to move and exposes another behind it, while a fork attacks two or more pieces simultaneously, with knight forks being especially common. A discovered attack reveals an attack from a piece behind the moving one, a discovered check adds the element of check, and a double check delivers check from two pieces at once, leaving only the king's move as a legal response. Zugzwang is a position in which any move worsens the player's situation, and a zwischenzug, or "in-between move," disrupts the opponent's expected sequence. Sacrifices—whether material sacrifices for tactical gain or positional sacrifices for long-term advantages, including exchange sacrifices—along with motifs like the "Greek gift" bishop sacrifice on h7 or h2, are central tactical tools.
Pawn structure shapes the entire middlegame. An isolated pawn has no friendly pawns on adjacent files and can be either a weakness or a dynamic asset, while doubled pawns sit on the same file and often restrict the side that owns them. A backward pawn cannot advance and lacks support, and a passed pawn—having no opposing pawns on its file or adjacent files—gains power as it advances, especially when supported by connected passed pawns or when threatening promotion in the endgame. A pawn chain is a diagonal arrangement of mutually supporting pawns whose base is often its weakest link, while hanging pawns are unsupported pawns on adjacent open files. Beyond pawns, positional concepts include outposts (squares in enemy territory safe from pawn attack), weak squares that cannot be defended by pawns, the bishop pair as an advantage in open positions, and the contrast between good and bad bishops, the latter blocked by their own pawns. Endgames with opposite-colored bishops are often drawish since the bishops cannot attack each other. Strategic principles guide these decisions: improve your worst-placed piece first, create two weaknesses to overstretch the defender, restrict opponent pieces before launching your own plans, prefer improving moves to reflexive trades, and trade pieces when ahead while complicating positions when losing. Initiative is the ability to dictate the course of play, counterplay is the defender's active resource, and the principle of "playing for two results" describes a position in which one side can only win or draw but cannot lose.