Mancala is played on a board with two rows of six shallow holes, and two larger holes on each side of the board. The holes nearest to you are yours, while the holes on the opposite side belong to your opponent. The large hole on the right is your mancala and the large hole on the left is your opponent's.
The object of the game is to capture as many stones and place them in your mancala as you can. The player with the most stones at the end of the game wins.
To play, a player picks one of their holes with stones in it and distributes these stones counterclockwise. Distribution of stones wraps around the board, placing a stone in the player's mancala along the way, but not placing one in the opponent's mancala (if the stones get that far).
If the last stone placed in a hole lands in your mancala, you get another turn. Otherwise it is your opponent's turn.
Also, if the last stone placed lands in one of your holes that is empty, and the hole opposite contains stones, you steal your opponent's stones. Your last stone and your opponent's stones are placed in your mancala, and it is then your opponent's turn.
The game is over when one player is out of stones, or when a player has more than half the stones in the game.
"Classic" Mancala is played just like this, with the game starting out with four stones in each hole (except for the mancalas). At the end of the game, any stones left on your side of the board are automatically placed in your mancala. The player with the most stones in their mancala is the winner.
This version of Mancala supports a few variations on these basic rules, with more being added as they are discovered.
The simplest variation is to change the number of stones in each hole. You can choose between 2 and 6 stones.
Another very simple variation is to disallow the stealing rule. In this case, if the last stone you distribute lands in one of your empty holes, that's it. Nothing happens and it's your opponents turn.
Variations at this point are broken up into game styles. Classic Mancala is a gathering style. That is, the object of the game is to capture, or gather, as many stones as you can. The player with the most stones in their mancala at the end of the game is the winner. A variation on the gathering style is to only count captured stones. Any stones left in play at the end of the game are ignored. This has an immediate impact on classic Mancala strategy!
Another style is to outlast your opponent, regardless of how many stones are in either mancala. The last player with any stones left is declared the winner.