Hnefatafl is Viking chess. It's pretty simple, and it looks pretty neat. It is also one of the only games where the two sides are uneven. Here's what the board looks like:
The big middle white piece is the King, and the purpose of the game is for the White Team to get the King to one of the four corner pieces, while the Black Team tries to kill the King.
Every piece moves like a rook and you can't jump over any pieces. You kill pieces by "sandwiching" them. Like this:
I kind of want to try it out. Anyway, it looks pretty cool.