Bao is a traditional mancala-style sowing game from East Africa where you attempt to eliminate all pieces from the opposing front row or leave them with no legal moves.
It is played on a board of four rows of eight pits. Each player controls the two rows on their side of the board. The row nearer the opponent is that player's front row; the other is their back row.
Each player has 32 seeds. Players sow seeds around their own sixteen pits, capture seeds from the opponent's front row, and relay-sow until the turn ends.
Unless otherwise stated, the rules below describe Abstract Play's default Zanzibar (standard) rules. The **Malawi (setup only)**, **Malawi (Bawo rules)**, and **Bao la Kujifunza** variants are described under Variants.
You win if either:
The two end pits of each front row are called the kichwa. The pits immediately beside them are the kimbi.
Each player also begins with a special front-row pit called the nyumba or house. It is the fifth pit from the player's left (equivalently, the fourth from the right) and is shown as a square pit on Abstract Play.
The two front-row pits directly opposite one another are paired for purposes of capture.
A front-row pit is a marker when the opposing pit contains at least one seed.
When captured seeds enter your side of the board, they are sown beginning with one of your kichwa:
The terms clockwise and counterclockwise always refer to the circuit around your own sixteen pits.
Red moves first; Blue moves second.
In the normal setup, each player begins with:
From Abstract Play's usual board orientation, the initial position is:
Blue — 22 in reserve Back: 0 0 0 0 0 0 0 0 Front: 0 2 2 [6] 0 0 0 0 ----------------------- Front: 0 0 0 0 [6] 2 2 0 Back: 0 0 0 0 0 0 0 0 Red — 22 in reserve
On Abstract Play, Red's nyumba is e2 and Blue's is d3.
The game begins in the kunamua phase. Once all the reserve seeds have entered the board, play continues in the mtaji phase.
There are two separate distinctions which are important not to confuse:
Thus, despite the shared word mtaji, a mtaji turn and the mtaji phase are not the same thing.
Capture is compulsory. If a mtaji turn is available, you must make one. You may kutakata only when no capturing move is available. Once a turn has begun as kutakata, no captures may occur anywhere during that turn, even if later sowing ends in a marker.
Whenever seeds are picked up for sowing, place them one at a time into consecutive pits around your own two rows in the required direction, starting from the required pit.
If the last seed of a sowing lands in an empty pit (ie, one which now contains only that one seed), the turn ends.
If the last seed of a sowing lands in a pit containing at least one seed (ie, one which now contains two or more seeds) and no capture is triggered thereby, pick up all the seeds from that pit and continue sowing in the same direction, beginning with the next pit. This continuation is called kuendelea or relay sowing.
Sowing continues, along with any triggered captures on a mtaji turn, until the turn ends by sowing into an empty pit or by one of the special stopping rules described below. Abstract Play checks the ordinary victory conditions after the turn has finished; emptying the opponent's front row does not itself interrupt sowing.
Captures can occur only from your front row.
On a mtaji turn, a capture occurs when a sowing ends in a front-row pit which:
Take every seed from that opposing pit. Those captured seeds are immediately sown on your own side, beginning in one of your kichwa.
Capture is compulsory: if at least one legal move begins with a capture, you may not choose a kutakata move instead.
If the capture was made from a kichwa or kimbi, the captured seeds must enter through the kichwa on that same side.
Otherwise:
Thus repeated captures can occur during one turn. A capture from a kichwa or kimbi may change the direction because the corresponding kichwa takes precedence over preserving the previous direction.
During the kunamua phase, each turn begins by taking one seed from your reserve and placing it into a nonempty pit of your front row.
There is an important restriction involving the nyumba: on a kutakata turn, you cannot begin from a working nyumba, even if it is your only occupied front-row pit. If you have no working nyumba, an occupied nyumba is eligible under the same seed-count restrictions as your other front-row pits.
This restriction does not prevent a mtaji turn from beginning at the nyumba: if the nyumba is opposite a nonempty enemy pit, placing your reserve seed there may be a compulsory capture.
If any occupied pit in your front row is opposite a nonempty enemy pit, you must place the reserve seed into such a pit and capture.
The reserve seed remains in the pit where it was placed. Take all the seeds from the opposing enemy pit and begin sowing those captured seeds from one of your kichwa.
If the capturing pit is a kichwa or kimbi, you must sow from the nearest kichwa; otherwise you may choose either kichwa for this first capture.
Further captures and relay sowing then proceed normally.
If no capture is available, the turn must be kutakata: no captures will be triggered during the turn even if later sowing would otherwise create the conditions for one.
The pits from which you can begin a kutakata turn during the kunamua phase are considered in the following order:
After placing the reserve seed into the chosen pit, sow from that pit in either direction. Because this is kutakata, no captures can occur for the entire turn even if the last seed of a sowing lands in an occupied pit opposite an opposing occupied pit.
A nyumba which still has its special status is working while it contains at least 6 seeds.
Most of the special nyumba rules apply only during the kunamua phase.
During a kunamua kutakata turn, if relay sowing ends in a working nyumba, the turn stops there rather than picking up and resowing the contents.
During a kunamua mtaji turn, if sowing ends in a working nyumba and no capture occurs there, you may either:
Playing the nyumba removes its special nyumba status when the turn is completed: from then on no special rules apply to it.
If a capture is possible from the nyumba, the capture takes precedence; you may not simply stop there or safari.
During kunamua, a capturing turn may begin at the nyumba normally.
A kutakata turn cannot begin at a working nyumba. If it is your only occupied front-row pit and no capture is available, you have no legal move and lose.
A non-working nyumba may be chosen according to the ordinary kunamua kutakata restrictions. Add the reserve seed, then pick up and sow its entire contents. This removes its special nyumba status.
Eligibility is determined before the reserve seed is added. For example, a nyumba containing 5 seeds may be chosen even though adding the reserve seed brings it to 6; all 6 seeds are then sown. Abstract Play does not offer two-seed taxation as a legal move under the default rules.
A pit loses its special nyumba status if:
Once the game reaches the mtaji phase, the kunamua rules for stopping in or optionally playing the nyumba no longer apply. An owned nyumba is picked up and sown like an ordinary pit.
Abstract Play nevertheless continues to track an unsown, uncaptured nyumba as a house until it is picked up and sown or captured. This retained status has two effects on kutakatia:
The mtaji phase begins after all reserve seeds have entered the board.
There are no longer reserve seeds to place. Instead, begin a turn by choosing one of your own pits containing at least 2 seeds and sowing its entire contents clockwise or counterclockwise.
As during kunamua, the turn itself will be either a mtaji turn (capturing) or a kutakata turn (noncapturing). Capture remains compulsory.
To begin a mtaji turn during the mtaji phase:
If any such capture is available, you must choose a capturing move.
A pit containing 16 or more seeds cannot begin a capturing turn. A turn beginning from such a pit is always kutakata, even if its sowing would otherwise finish in a marker.
Once a turn has begun as kutakata, it remains noncapturing for the entire turn.
If no capturing move exists, you must kutakata.
If at least one unblocked front-row pit contains 2 or more seeds, you must begin from the front row. Only if no such pit exists may you begin from a back-row pit containing 2 or more seeds.
Two additional restrictions apply:
Merely picking up the last seeds from your front row does not make a move illegal: the ensuing sowing may put seeds back into that row. The second restriction concerns the position when a back-row relay pickup would occur.
These restrictions can leave you without a legal move. An otherwise compulsory front-row start does not give you permission to start from the back row merely because its sowing would violate the empty-front-row restriction.
Sowing continues by the normal relay rules, without captures.
During the mtaji phase, a kutakata move can sometimes block one of the opponent's front-row pits. Abstract Play marks such a pit with an outline.
After a player completes a kutakata turn, Abstract Play considers all the capture moves that that same player would have if they could move again immediately from the resulting position. If there is at least one such capture move, and every one of them makes its first capture from the same opposing pit, AP attempts to block that pit.
A pit is not blocked if:
While a pit is blocked, the following rules apply:
The block disappears if:
Thus a player may sometimes remove a block during a capturing move of their own, either by sowing from the blocked pit or by capturing the opposing pit.
You lose if your front row is empty when a turn finishes.
You also lose if, at the beginning of your turn, you have no legal move. During kunamua, this includes having only a working nyumba in your front row when no capture is available. During mtaji, it can happen if all your remaining seeds are isolated one seed per pit, or if the restrictions on kutakata exclude every otherwise possible move.
Temporarily emptying your front row while picking up and sowing seeds is not itself an immediate loss, although the mtaji kutakata restriction on back-row relay pickups still applies.
Bao can produce very long relay sequences. Abstract Play uses a fixed cutoff rather than proving that a certain move could continue forever.
AP counts the cumulative number of seeds distributed during the move. After a sowing finishes, if play reaches the point of picking up seeds for another ordinary relay, AP checks whether this count exceeds 192, equivalent to twelve circuits of the player's sixteen pits. If it does, AP declares the move infinite and the player making it loses.
This is not a strict maximum of 192 seed placements: captures and stopping conditions are processed before the cutoff check, so a move can exceed that count without being declared infinite if it ends before reaching the check.
This is Abstract Play's older Malawi variant, now labelled Malawi (setup only) and marked as deprecated.
Each player begins with:
It otherwise follows the default Zanzibar rules, with one additional difference: the working-house threshold is 8 seeds rather than 6. This applies both to the kunamua house rules and to protection against being blocked.
Despite its name, this variant therefore changes both the starting position and the house threshold. It does not include the additional Bawo rules described below.
This variant uses the same 8-seed kuu, two neighboring pits with 2 seeds each, and 20 reserve seeds per player. A kuu is working while it retains its house status and contains at least 8 seeds.
Abstract Play begins from this fixed position; it does not include an advanced opening-distribution procedure.
The rules are as described above, with the following changes.
When no capture is available, choose your starting pit in this order:
Unlike the default rules, having a working kuu does not allow you to choose a singleton while another non-house front-row pit contains 2 or more seeds. A kuu which still retains house status is excluded from the first two options even if it is no longer working.
While your own kuu is working and the enemy pit directly opposite it is occupied, you may not capture the opponent's kuu.
This restriction applies in both phases and to later captures within a turn as well as the first capture. AP checks the current position when each capture would occur. The opponent's kuu remains protected by this rule even if it contains fewer than 8 seeds, provided it still retains its house status.
Other legal captures remain compulsory.
A capturing turn must begin from a pit containing 2 through 14 seeds. A turn beginning from a pit containing 15 or more seeds is always kutakata and cannot capture later in the turn.
When no capture is available, if you still have a working kuu and no earlier turn has begun at that kuu while it retained its house status, you must begin your kutakata turn from it. Sow its entire contents.
For this purpose, AP counts an earlier capturing turn begun at the kuu as having used it, even though such a turn initially sows captured seeds rather than lifting the kuu's own seeds.
The ordinary restrictions on mtaji kutakata still apply, including sowing toward the centre from a sole occupied kichwa and the prohibition on back-row relay pickups while the front row is empty.
Bao la Kujifunza skips the kunamua phase entirely.
At the start:
The game therefore begins immediately under the mtaji-phase rules.
Generated by ChatGPT; reviewed by Samraku. I'm fairly confident it has the rules right according to the AP code (or at least close enough to compete with existing rules explanations for completeness, correctness, and clarity), but not very confident how those rules relate to traditional formulations. Some of the more esoteric terminology (like kuendelea) I also didn't verify.