Hnefatafl

Norse Scandinavia. The Vikings played it before chess reached them.

Who moves first?

The two sides in this game aren't the same, so choosing who moves first also chooses who plays which side.

You don't need an account or an email, and there's nothing to install. You'll get a link to send to the person you want to play.

How to play

The board

Eleven squares by eleven. Twenty-four attackers stand in groups along the four edges.
Twelve defenders and their king start in a diamond at the centre, with the king on the middle square.
The attackers move first.

Moving

Every piece moves like a rook in chess: any distance in a straight line, up, down or across.
Nothing moves diagonally and nothing jumps over anything.
The king moves the same way as everybody else.

The five special squares

The four corners and the centre square are not ordinary squares. Only the king may stand on them.
Nobody else may enter a corner or pass through one. The centre square can be crossed by anyone once the king has left it.
They also help capture. A piece caught between an enemy and one of these squares is taken.

Taking pieces

You take a piece by getting your own on both sides of it, in a straight line. Diagonals never capture.
Your move has to close the trap. Stepping into the gap between two enemies yourself is safe.
The edge of the board is not a side. A piece with its back to the edge is not trapped by one enemy.
The king helps capture, like any other piece.

Taking the king

To take the king you need all four sides at once, so he's harder to take than any other piece.
Next to the centre square, three attackers are enough, because the empty centre counts as the fourth.
On the edge of the board the king cannot be taken at all.

Winning

The defenders win by walking the king to any corner.
The attackers win by taking him.
A game can also end in other ways. You'll find them in the next section.

Which rules do we use?

We play Copenhagen Hnefatafl, on an 11 × 11 board. It's the World Tafl Federation's tournament standard, agreed in 2012.

Which rules you play matters more here than in most games. Nobody knows how the Vikings played. Every modern version of tafl is a reconstruction, and they disagree about rules that decide games.

Copenhagen adds four rules to Fetlar, the standard it was built from.

The shieldwall: A row along the edge is captured together when it is bracketed at both ends and each piece in it has an enemy in front.
The exit fort: The king wins by reaching the edge inside a formation the attackers cannot break.
Encirclement: The attackers win by enclosing the king and every defender in an unbroken ring.
Repetition: Repeating a position forever is a loss for the king's side.

There are two more things to know. Here the king is armed, so he helps capture. And a player with no legal move loses, unlike stalemate in chess, which is a draw.

The full rules are published by Aage Nielsen at aagenielsen.dk.