What was the ancient Egyptian game senet?

The ancient Egyptian game we call senet (hieroglyphs: snt) was a board game which was very popular among all classes. The name means "passing", but the rules of the game are not known today.

Pictures from tombs show the board marked out in squares and two sets of playing pieces; one set is tall and tower-shaped, the other set is shorter and more like a cotton-reel in shape.

The game came to symbolise the "passing" of a deceased person into the afterlife, which explains why it is shown being played by the dead person against an invisible opponent on the walls of tombs.