Twenty squares: rules and history

Twenty squares in a minute

1. The goal

   A race: bring all seven of your pieces along the path and off the end before your opponent does.

2. Sticks, not dice

   Throw four sticks and count the light sides, 0 to 4: that is how far you move. A 0 does not move.

3. Moving

   Move one piece by the whole throw. In the shared lane, landing on an enemy piece sends it back off the board.

4. Winning

   Bear each piece off with an exact throw. The first to bear off all seven wins.

The rules, step by step

Eleven rules, each with a picture of what happens on the board.

1. 1

   The board and the path

   Twenty squares: a block of three rows of four, with the middle row carried on for eight more. You enter on your own outer row, run it outward (squares 1 to 4), turn into the middle row and run it to the end (squares 5 to 16), then off.

   Source: The "3 × 4 + 8" board: Carter cards 345 and 593 (Griffith Institute). The route: Kendall 1982: 265; Finkel 2007: 27; Crist et al. 2016: 98–99
2. 2

   The pieces

   Each player has seven pieces. All of them start off the board, waiting to enter.

   Source: Seven a side is the number in today's common rules (royalur.net); Babylonian tablet BM 33333B names five (Finkel 2007)
3. 3

   The sticks

   = 3

   Four sticks, each light on one side and dark on the other. The throw is the number of light sides: 0, 1, 2, 3 or 4.

   Source: Our choice: the same sticks as Sawah's senet. Their chances equal those of four tetrahedral dice from Ur — arithmetic, not a historical claim
4. 4

   Entering

   1234

   A waiting piece enters on the square that matches the throw: a 1 onto square 1, a 3 onto square 3. Entering is a move like any other.

   Source: Today's common rules (royalur.net)
5. 5

   Moving

   5678910

   Move one piece forward by the whole throw. You cannot land on a square where your own piece stands.

   Source: Today's common rules (royalur.net)
6. 6

   Taking a piece

   567

   In the shared lane (squares 5 to 16), landing on an enemy piece takes it: it goes back off the board and must enter again. Your first four squares are yours alone, so nobody can reach you there.

   Source: Today's common rules (royalur.net); the tablet says nothing of capture (Finkel 2007)
7. 7

   Marked squares are safe

   56789

   A piece on a marked square (4, 8, 12, and 16) cannot be taken. If the only way forward lands on an enemy piece sitting on a mark, that move is not allowed.

   Source: Today's common rules (royalur.net); the marks on squares 4, 8, 12 and 16 follow Tutankhamun's box 593 (Carter card 593-3)
8. 8

   A marked square gives another throw

   56789

   End your move on a marked square and you throw again at once.

   Source: Today's common rules (royalur.net); Finkel (2007: 26) suggests "rosette = a second throw" was the earlier everyday play
9. 9

   Bearing off

   13141516➜

   A piece leaves the board with an exact throw: from square 16 on a 1, from 15 on a 2, from 14 on a 3, from 13 on a 4. A throw that would carry it further is not allowed.

   Source: Today's common rules (royalur.net)
10. 10

    A 0, or no move

    = 0

    A throw of 0 moves nothing, and neither does a throw with no allowed move. Either way the turn passes to your opponent.

    Source: Today's common rules (royalur.net)
11. 11

    Winning

    141516➜

    The first player to bear all their pieces off the board wins.

    Source: Today's common rules (royalur.net)

Four ways to play: what's the difference?

Before you play, you choose the rules. Sawah rules are the base and the easiest start; the other three each change one thing, and each change has a source. Here is every difference, where it comes from and what it does to the game — and each set has a short lesson that teaches the difference hands-on.

1. For beginners

   Sawah rules

   The Egyptian board, 7 pieces; a mark is safe and gives another throw.

   The base

   These are the rules every other set is measured against.

   Where does it come from?

   Today's common rules for the Royal Game of Ur, played on the Egyptian board of Tutankhamun's box 593, with the marks where that box has them.

   What does it change in play?

   A race with real choices: when to take a piece, when to sit on a mark, and when to hurry home.

   Source: Carter card 593-3 (the board); royalur.net (the rules)
   Play with these rulesLearn it in a short lesson
2. For experts

   The Ur board

   A 3×8 board with rosettes on squares 4, 8 and 14.

   What changes from Sawah rules?

   • The Ur board instead of the Egyptian one: two blocks joined by a two-square bridge
   • A path of 14 squares: four of your own, eight shared, and two of your own again at the end
   • Rosettes on squares 4, 8, and 14

   Where does it come from?

   The shape of the boards Leonard Woolley found in the Royal Cemetery at Ur, such as British Museum BM 120834, with the route played today.

   What does it change in play?

   A shorter path and a shorter shared lane: fewer squares to meet on, and the middle rosette becomes the square to hold.

   Source: British Museum BM 120834; royalur.net (the route)
   Play with these rulesLearn it in a short lesson
3. For experts

   The Babylonian tablet

   5 pieces a side, the number the cuneiform tablet names.

   What changes from Sawah rules?

   • 5 pieces a side instead of seven

   Where does it come from?

   Tablet BM 33333B, written in 177/176 BCE, gives each side five pieces named after birds. It says nothing of the route, capture or safety, so everything else stays as in Sawah rules.

   What does it change in play?

   Fewer pieces make a quicker game, with fewer pieces to guard and fewer to bring home.

   Source: Finkel 2007: 16–32
   Play with these rulesLearn it in a short lesson
4. For experts

   Marks give a throw only

   A mark gives another throw but does not protect the piece on it.

   What changes from Sawah rules?

   • A marked square still gives another throw, but it is not safe: a piece on it can be taken

   Where does it come from?

   Irving Finkel suggests that the simple "rosette = a second throw" was the earlier everyday play. Here a mark keeps its extra throw and loses its safety.

   What does it change in play?

   No square in the shared lane is safe, so the game is sharper: a piece sitting on a mark can be taken like any other.

   Source: Finkel 2007: 26
   Play with these rulesLearn it in a short lesson

All four are modern reconstructions, because no Egyptian rules survive and the Babylonian tablet does not give a whole game.

The chance of each throw

Assuming each stick lands light side up half the time — a modern assumption. The chances (1, 4, 6, 4 and 1 in 16) are the same as for four tetrahedral dice from Ur: arithmetic, not a historical claim. The average throw is 2, and one throw in sixteen is a 0.

What we know about twenty squares

Every fact below comes with its source and how sure it is. Dates are those given by the museum or scholar named.

1. c. 2600–2400 BCE · Ur, Mesopotamia

   Consensus

   Leonard Woolley found boards of this game in the Royal Cemetery at Ur, excavated from 1922 to 1934. The best known is in the British Museum (BM 120834).

   Source: British Museum, BM 120834

2. The Ur board

   Consensus

   A block of four squares by three joined to a block of two by three by a two-square bridge, with rosettes at the ends of the outer rows and in the middle of the shared lane.

   Source: British Museum, BM 120834

3. After about 2000 BCE

   Consensus

   A "head-and-tail" board replaced the Ur shape: a block of three rows of four, with the middle row carried on for eight more squares — twelve shared squares, and four of each player's own at one end. Howard Carter wrote it "3 × 4 + 8".

   Source: Finkel 2007: 17; Carter cards 345 and 593 (Griffith Institute)

4. The marked squares

   Consensus

   Where squares are marked, it is every fourth square of the path: 4 (on both private rows), 8, 12 and 16. Some boards mark all five, others only 8, 12 and 16, and many none at all: Crist and colleagues count 15 marked boards and 16 plain. The rosette on our board is our own sign; the ancient marks differ from board to board.

   Source: Crist, Dunn-Vaturi & de Voogt 2016: 91, citing Pusch 2007: 71 (second-hand)

5. The tomb of Tutankhamun

   Consensus

   Tutankhamun was buried with at least four double-sided game boxes: senet on one face, twenty squares on the other.

   Source: Crist et al. 2016; JE 62058–62061

6. 3 November 177/176 BCE · Tablet BM 33333B

   Consensus

   Tablet BM 33333B was written by Itti-Marduk-balāṭu on 3 Arahsamnu, year 135 of the Seleucid era, copied from a tablet of Iddin-Bēl. It gives five pieces a side named after birds (Swallow, Storm-bird, Raven, Rooster, Eagle), dice of an ox and a sheep knucklebone, entry throws, and stakes won or lost on the rosettes. It says nothing of the route, capture, safety, extra throws or bearing off.

   Source: Finkel 2007: 16–32

7. The rules

   Consensus

   No Egyptian rules for the game survive. The popular modern rules (seven pieces, four two-sided dice counting 0 to 4, a rosette that is safe and gives another throw, capture, an exact exit) come from the board's shape and from modern play, not from the tablet.

   Source: Crist et al. 2016: 98–99; Finkel 2007: 27; royalur.net/rules

8. The route

   Consensus

   The accepted Egyptian route: each player enters their own row of four, then both race down the shared lane of twelve and off the end. For the route on the tablet, Finkel writes that "there is no evidence on the point".

   Source: Kendall 1982: 265 (second-hand); Finkel 2007: 27; Crist et al. 2016: 98–99

9. Until the 1950s · Kochi, India

   Second-hand report

   A game of the same family was played by Jewish women in Kochi (Cochin), with cowrie shells, until the community emigrated to Israel in the 1950s.

   Source: Irving Finkel, as reported by TIME in 2008 — a press report, not a scholarly publication

Tutankhamun's game boxes, and one at the Met

What was it called?

• "Twenty (squares)"Consensus

  The safest name. The Turin Papyrus labels a double board "Uniting of the twenty squares".

  Source: Pusch 1977: 209–11, via Crist et al. 2016 (second-hand)

• "Tjau" (ṯꜣw, "robbers")Wrong

  A nineteenth-century identification from the tomb of Aba. Crist and colleagues call it incorrect, and Pusch re-read the word as "marbles".

  Source: Crist et al. 2016; Pusch 2007: 84 (second-hand)

• "Aseb" (ꞽsb)Uncertain

  Possible only if a scene at Beni Hasan shows this game; it has been compared with the Akkadian "patti apsu". Uncertain.

  Source: Kendall 1982, via Crist et al. 2016 (second-hand)

Common mistakes

• It is said: The Babylonian tablet gives the rules people play today.

  In fact: It gives five pieces, dice, entry throws and stakes, but nothing of the route, capture, safety, extra throws or bearing off (Finkel 2007).

• It is said: We know how the Egyptians played it.

  In fact: No Egyptian rules survive (Crist et al. 2016: 98–99; Finkel 2007: 27). Every way of playing it today is a reconstruction.

• It is said: Every board has the same marked squares.

  In fact: Some boards mark five squares, some three, and many none (Crist et al. 2016: 90–91).

• It is said: The rosette on Sawah's board is the ancient sign.

  In fact: It is our own design. The ancient marks differ from board to board.

Ancient dates are estimates; each is given as the museum or scholar named beside it gives it.

Sources

1. Finkel, I. L. 2007. “On the Rules for the Royal Game of Ur.” In I. L. Finkel (ed.), Ancient Board Games in Perspective, 16–32. London: British Museum Press.
2. Crist, W., Dunn-Vaturi, A.-E. & de Voogt, A. 2016. Ancient Egyptians at Play: Board Games across Borders. London: Bloomsbury.
3. Griffith Institute, Oxford. Howard Carter archive: object cards 345, 393, 585r, 593.
4. The Metropolitan Museum of Art. Game box for senet and twenty squares, 16.10.475a–l.
5. British Museum. The Royal Game of Ur, BM 120834 (W_1928-1009-378).
6. Kendall, T. 1982. “Schliemann’s ‘Tropfen’ and the Game of Twenty Squares.” — cited via Crist et al. 2016. · second-hand
7. Pusch, E. B. 1977 and 2007 — cited via Crist et al. 2016. · second-hand
8. Royal Game of Ur rules as played today (royalur.net).
9. TIME, 2008: I. L. Finkel on the game in Kochi (Cochin) — a press report. · second-hand

References are given as published, in their original language. Works marked second-hand were read through the citation of another work. Wikipedia was used only to reach them and is not cited as a source.