Pawn promotion is one of those special chess moves that might be a bit complicated to players that are still learning the game. This article will explain what happens when a pawn reaches the other side of the board, including all the chess rules related to this problem.
When a pawn reaches the other side of a chess board, it is completely removed from the board. Promoted pawns are replaced by a queen, rook, bishop, or knight of the same color. These promoted pieces take the place of the pawn on the board.
Most commonly, players will choose to promote their pawns into a queen, as it is the strongest chess piece. It is possible to have two queens on the board, or to have even more queens than that. In any case, pawns that reach the other side are essentially ‘transformed’ into a stronger chess piece.
A Pawn Is Removed From The Board
Once a pawn manages to reach the far side of the board, it transforms from a rather unremarkable piece onto a powerhouse. Whereas a pawn can barely walk and attack, the pieces it can promote into are a force to be reckoned with.
The other side of the board is always on the eighth rank, i.e. six squares form the starting position of a pawn. Black pawns aim to reach the opposite side, after which they are also able to promote themselves.
The moment the other side is reached, the situation will look a little something like the example below:

Once the white pawn manages to reach line 8, it has to be completely removed from the board. The square where the pawn is promoted is also the square where the new chess piece is placed. Basically, the ‘better’ piece takes the position of the promoted pawn.
Another Piece Takes The Pawn’s Place
The player that decides to promote their pawn may choose their own ‘promoted piece’, with some limitations. As mentioned, the pawn is only able to promote into a ♕ Queen, ♖ Rook, ♗ Bishop, or ♘ Knight. It is not possible to promote a pawn into a king, which would be a major liability.
After deciding which piece the pawn should promote into, the pawn is completely removed from the board. The new piece takes the exact place the pawn was in when it was promoted. In our example, that would be square d8:

If you wish to follow chess notation rules, the promotion of the pawn in the example above would be noted as ‘d8Q’. This basically says that a new queen is created, but only after the pawn has moved to square d8 on the board. Learn more about notating special events in chess here.
Also, remember that pawn promotion always happens in a single turn. Moving the pawn from d7 to d8 and then promoting it to a queen is seen as one full turn.
What Chess Rules Forbid With Pawn Promotion
Keeping a promoted pawn on the board after it reaches the other side of the board is illegal. Chess rules forbid a pawn to remain on the board after it has promoted, it should always be replaced with a queen, rook, bishop, or knight. Players get to decide when the pawn is moved to the other side.
If an opponent’s piece blocks the eighth rank with one of their own pieces, a pawn is not allowed to move vertically to reach the other side. Remember that a pawn is only allowed to attack forward in a diagonal line, so attacking forward in a vertical line to take the knight wouldn’t be possible in the example below:

Since the pawn may only attack diagonally, placing a piece right in front of the pawn is a logical defense mechanism. In the example above, the black king would move towards the pawn to take it. The white king can’t do anything about this, because it wouldn’t be able to take the knight in time.
Once the pawn is taken by black, the game would end in a stalemate. That’s because it’s not possible to win a game with just a king and knight against another king. Being able to promote the pawn was the last hope for white in the example situation!
Getting Your Pawns To The Other Side
Moving your pawns to the other side of the board is essentially a kamikaze mission. The pawn’s only objective is to reach the other side and self-destruct into a queen, rook, bishop, or knight.
Getting those pawns to the other side is like a caterpillar turning into a butterfly, as it does give the pawn more strength after ‘transformation’. It changes from a slow, immobile piece and transforms into a strong attacking piece like a queen.
That’s why it’s always worth it for a player to think about their pawn structure. Playing the pawn game can definitely help you win a longer chess match. Imagine defending that one pawn and helping it all the way to the far side of the board. While it’s not easy, the payoff of having two, three, or even four (or more) queens can be an amazing strategic advantage.
But always remember to remove the pawn the second it promotes into a stronger chess piece. Those are the rules of chess, and not following them would make your chess moves illegal. Never forget this when beefing up those pawns!