Our game Seed Pits is played on a board with two rows of six hollows and a store at each end. If you have seen a wooden board like that in a toy shop, it was probably sold as "Mancala".
That name is a little misleading. Mancala is not one game. It is a whole family, with hundreds of members, and it is one of the oldest and most widely played kinds of board game in the world.
What the games share
The word comes from an Arabic verb meaning "to move". All the games in the family work in the same basic way.
There is a board of pits, usually in two rows, sometimes three or four. The pits hold counters: seeds, pebbles, shells or beans. On your turn you lift all the counters from one pit and drop them one at a time into the pits that follow, going round the board.
This is called sowing, and the farming image is deliberate. In many places the counters are real seeds.
What happens when the last seed lands is where the games differ. It may capture something, earn another turn, or carry on sowing from where it stopped.
How old is it?
Nobody knows for certain. Rows of pits cut into stone have been found at ancient sites in Africa and the Middle East, and some people believe they are game boards thousands of years old. It is hard to be sure. A row of hollows in a rock might have been used for a game, or for something else entirely.
What is clear is that sowing games have been played in Africa and across parts of Asia for many centuries, and that they spread along trade routes. Enslaved Africans carried them to the Caribbean and the Americas, where versions are still played.
A game needs almost nothing. Two rows of holes scooped in the ground and a handful of pebbles will do. That is part of why it travelled so far.
Some members of the family
Oware is played in West Africa and the Caribbean, with two rows of six pits and four seeds in each. Captures are made by bringing an opponent's pit to exactly two or three seeds. It is regarded as a serious game of skill, and there are clubs and tournaments.
Bao comes from East Africa, especially the coast and Zanzibar. It uses four rows of eight pits and has complicated rules. It is often described as the most demanding game in the family.
Congkak and sungka are played in Malaysia, Indonesia and the Philippines, on long boat-shaped boards with seven pits a side. Traditionally shells are used.
Pallanguzhi is played in southern India and Sri Lanka, with two rows of seven.
There are many more. Rules vary from village to village, as they do with any game passed on by playing.
The version on this site
Seed Pits uses the rules usually called Kalah. This is the version most often sold in boxed sets in Europe and North America.
It is a twentieth-century adaptation. An American, William Julius Champion, worked out the rules and began selling the game in the 1940s. He simplified things compared with many traditional games, which is one reason it caught on.
The rules are these. Six pits each, four seeds in every pit. You sow anticlockwise and drop a seed in your own store as you pass, but never in your opponent's. If your last seed lands in your store, you go again. If it lands in an empty pit on your side, you capture it along with whatever is in the pit opposite.
Those two special rules, the extra turn and the capture, are what give the game its character.
What makes it a good game
Every move changes everything. Sowing from one pit adds a seed to several others. A pit that was about to give your opponent an extra turn may suddenly have one seed too many.
It is all counting. There is no luck and nothing hidden. A player who counts carefully will beat one who does not.
You can plan combinations. A move that ends in your store gives you another move, which may end in your store again. Stringing these together is the strongest thing you can do. At the very start, the third pit from the left has exactly the right number of seeds to reach your store.
Solved, but not for people
Computer scientists analysed this version completely around the year 2000. With six pits and four seeds each, the first player can force a win with perfect play.
That need not trouble anyone. The winning line is far too long and exact for a person to follow, and one miscount hands the advantage back. Between two people at a table, it is a fair fight.
If you want to be scrupulous, play two games and take turns to go first.
Why it belongs here
Every game on TwoSide is for two people sharing one screen. Seed Pits may be the oldest idea among them. People were playing something very like it, with real seeds in hollows in the ground, long before there were screens, or chess, or playing cards.
Most HTML5 games are a few years old at most. This one has been tested by more players, over more centuries, than almost any other game you could name. It takes about eight minutes, and it rewards counting. Start with the third pit.