What Is Forsyth–Edwards Notation (FEN) in Chess? A Simple Guide for Beginners

If you’re diving into The Password Game, solving chess puzzles, or just curious about how chess positions are recorded, you might have come across a weird string like this:

rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R w KQkq - 2 2

Don’t worry. That’s not a secret code. It’s a FEN, and it’s one of the most useful tools in chess.

What is FEN?

FEN stands for Forsyth–Edwards Notation.
It’s a short string that describes a specific position on a chessboard so a computer (or a person) can instantly recreate the game at that point.

Think of FEN like a snapshot of a chess game at any moment.

A FEN Has 6 Parts

Let’s use this sample FEN:

rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 2 2

And this is the chess position of that FEN:

Each section is separated by a space. Here’s what each part means:

1. Piece Placement

rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R

• Describes the position of pieces, rank by rank (top to bottom = ranks 8 to 1).
• / separates the rows.
• Letters = pieces:
  • K = King
  • Q = Queen
  • R = Rook
  • B = Bishop
  • N = Knight
  • P = Pawn
    (Lowercase = Black, Uppercase = White)
• Numbers = empty squares.

Example:

• pppp1ppp → 4 pawns, 1 empty square, then 3 pawns.

2. Active Color

b

• Whose turn it is.
• w = White to move
• b = Black to move

3. Castling Rights

KQkq

• K = White can castle kingside
• Q = White can castle queenside
• k = Black can castle kingside
• q = Black can castle queenside
• - = No castling rights

4. En Passant Target Square

-

• If a pawn moved two squares forward last turn, this tells whether en passant is available.
• Example: e3 means White just played d2-d4, and Black can capture en passant on e3.
• - means no en passant move is possible.

5. Halfmove Clock

2

• Counts moves since the last pawn advance or capture.
• Used to determine if the 50-move rule applies (for draws).

6. Fullmove Number

2

• Increments after Black’s move.
• So if it says 2, it means this is White’s move in turn 2.

Why Is FEN Useful?

• Chess engines use it to load specific positions.
• It helps people resume saved games or share puzzles.
• It’s essential for programming chess bots or analyzing games.
• And yes… it shows up in The Password Game!

TL;DR

A FEN looks complicated, but it’s just a way to store a chess position in 6 parts:

Part	Meaning
1	Piece positions on board
2	Whose turn it is
3	Castling availability
4	En passant target
5	Halfmove count
6	Fullmove number

Bonus: Try FEN Yourself!

Copy a FEN and paste it into:

👉 https://lichess.org/analysis

Click the FEN button to instantly see the position come to life on a real board!