The pawn is the smallest piece, but is one of the most important pieces. They are set up all along rows 2 (white) and 7 (Black). Pawns can move one space forward or one space diagonally if they are capturing. Pawns are worth 1 point each. They do not need to be represented by a letter in algebraic notation, though some use P. Pawns are usually differentiated by the file at which they begin; so a pawn that started out on a2 would be called the a-pawn, or rook's pawn.
If a pawn is on its starting row, it can move two spaces in addition to one.
If a pawn reaches the other side, it can change to any piece it wants, with the exception of a king or another pawn (although the queen is by far the most common). This is known as promotion. Promotion to a rook, knight, or bishop is called Underpromotion.
A pawn can also perform en passant. In order to do this, a pawn must have just advanced two squares, placing it adjacent to a pawn of the opposite color that could have captured it, had it moved one square. The opposite-color pawn moves to the place it could have captured the pawn that just moved, and removes it from the board.
The most possible moves a pawn can have at once is four. This is when it is in the second row, has two empty spaces ahead of it, and has enemy pieces to the left and right of the space directly ahead of it. The pawn can move one space forward, two spaces forward, or capture either enemy piece.
Aside from promotion and en passant, described above, pawns can be mighty tools despite their individual weaknesses. They are at the heart of the strategic depth of chess, and their placement can heavily influence the outcome of a game. For example, a line of diagonally-placed pawns can be difficult to disrupt by the same colored bishop, and can seriously hinder an opponent's strategy. In the endgame and in front of the king after casting especially, pawns are strongest in straight lines. This is because they do not leave gaps in front of them as they can protect each other. The pawn's weakness, however, stems from the fact that one that is badly-placed cannot retreat to a better position, it can only advance further. A pawn that is not protected by other pawns of the same color is frequently referred to as an isolated pawn.
A blue puzzle piece on the left, a white pawn on the middle and a black spade on the right is the symbol of games on the desktop.