Promotion is what happens when a pawn reaches the far side of the board: it is replaced by a queen, rook, bishop or knight. It is how a single pawn can decide a game. Below is the rule in full, when a piece other than a queen is the right choice, and then puzzles from real games, matched to your puzzle rating, where promoting a pawn is part of the solution.
When a pawn reaches the last rank, the eighth for White and the first for Black, it must be exchanged, as part of the same move, for a queen, rook, bishop or knight of its own colour. It cannot stay a pawn, and it cannot become a king. The new piece stands on the square the pawn reached.
Your choice does not depend on what has been captured. You can have two queens, or three knights, on the board at once. A pawn can also promote by capturing diagonally onto the last rank, and the promotion move can give check or checkmate straight away.
Choosing anything but a queen is called underpromotion. The queen is the strongest piece, so this is rare, but there are two situations where it is the right choice.
The first is the knight check. Put a white pawn on d7, a black king on f7 and a black queen on b7. Promoting to a queen does not give check, but 1.d8=N+ does, and the new knight also attacks the queen on b7. Black cannot capture on d8 and has to move the king, and 2.Nxb7 wins the queen.
The second is avoiding stalemate. With a white king on f2 and a white pawn on b7 against a lone black king on h1, 1.b8=Q is stalemate: the queen's long diagonal takes away h2, and Black has no legal move. 1.b8=R keeps the win, because a rook does not cover that diagonal. Black's only move is 1...Kh2, and 2.Rh8 is checkmate.
Most promotion puzzles are about getting a pawn through, not about the choice of piece. The key moves are usually the ones before the promotion: a sacrifice that removes the blocker, a deflection that drags away the piece guarding the queening square, or a check that gains the tempo the pawn needs. Pawn races, where both sides try to promote first, are common too, and counting the moves exactly is the whole skill.
In the puzzles, when your pawn reaches the last rank you choose the piece from the promotion panel. The solution expects a particular piece, and now and then the right answer is a knight or a rook.
The most common is promoting to a queen by reflex without checking for stalemate, especially when the opponent has only a king left. The second is pushing the pawn when the queening square is still covered, so the new piece is captured at once. The third is miscounting a pawn race and forgetting that the opponent's new queen may arrive with check. Before promoting, ask what the new piece attacks, whether it can be taken, and what the opponent can do next.
In each puzzle, find the passed pawns first, then the pieces that stop them, and ask how to remove or distract those pieces. If you are stuck, the hint shows the piece first, then the move. After you solve, the full line appears beside the board.
For mixed tactics at your level, use Puzzle Training. Puzzle Storm trains speed, the Woodpecker Method repeats a fixed set until it is automatic, and Elo Maxing serves the motif you are weakest at. Pattern Drill works from positions in your own games. Endgames with passed pawns often turn on zugzwang, a new queen can fall to a skewer, and the other special pawn rule is on the en passant page. For more on rated solving, read rated chess puzzles explained.
When a pawn reaches the last rank it is replaced, as part of the same move, by a queen, rook, bishop or knight of the same colour.
Yes. Promotion does not depend on which pieces have been captured, so you can promote to a second queen, or more.
No. A pawn can only become a queen, rook, bishop or knight.
Promoting to a rook, bishop or knight instead of a queen. It is right when a knight gives a winning check or when a queen would give stalemate.
Yes. A pawn that captures diagonally onto the last rank promotes on that same move.