Twenty squares, also known as the Game of Ur, the Royal Game of Ur or the Sumerian game, is currently the oldest known board game in the world, and it is certainly one of the best understood of the known ancient games.
The earliest known versions of the 20 Squares game have been found in sites dated to the Bronze Age of 2500 BC: Woolley's excavations of the Royal cemetery of Ur in present-day Iraq, and about the same time in the Shahr-e Sokhta grave site in Iran. Versions of the game have been identified as graffiti carved into the base of sculptures.
Playing 20 Squares
The process of playing 20 Squares comes closest to the modern game of backgammon, and it may very well be that game's precursor. The game is played on a flat board with twenty decorated squares arranged in two and three rows. Two players move their pieces along a planned track, according to the throw of the dice, commonly knucklebones.
By the way, knucklebones, or astralagi, were commonly the knucklebones of sheep or goats, or carved bits of stone or bone or other material into a four-sided die. Knucklebones were a game themselves, something like what kids play called jacks--but that's another story.
Rules of 20 Squares
It's very rare that archaeology can tie a board, its pieces and its rules altogether. But the rules of 20 squares game, as it was played in the second century BC, anyway, are known due to a stroke of luck. The rules were found inscribed on a cuneiform tablet (BM 33333B), found somewhere in Mesopotamia and today deposited in the British Museum where Mesopotamian curator and ancient game expert Irving Finkel translated it. According to those rules, 20 Squares is a race game.
Players take turns rolling the dice and moving around the board in opposite directions, and they meet briefly and dangerously in the middle row. If a player land on a star, she gets a second turn; if a player lands on an opponent's piece in the middle row, the opponent is captured and sent back to the her starting point. The player who moves all of her pieces off the board first wins the game.
The people who played 20 Squares were of all ranks and status in the societies: boards have been found in cemetery contexts, in ordinary residences and in palaces. There may well have been divinatory or religious reasons for playing the game: these notions come from the decorative icons displayed on the boards, which include stars and zodiac figures in some cases. See Romain 2000 for a discussion of the notions as proposed by Irving Finkel.
Archaeology and 20 Squares
To date, about 100 examples of 20 Squares boards have been found in archaeological contexts, including examples from Turkey (Sam'al), Iraq (Khorsabad, Bismaya), Israel (Gezer, Beth Peleth, Beth Shemesh, Megiddo, Hazor), Jordan (Tell Beit Mirsim, Tell es-Saidyeh) Iraq (Ashur), Syria (Tell Halaf, Hama), Cyprus (Enkomi), Egypt (Kurna, Saqqara, Thebes, Drah Abu el-Naga, Deir el-Medineh), and Lebanon (Kamid el-Loz).
Game boards often had another game on the back of the board, most often the Egyptian game of Senet but occasionally 58 Holes. A recent statistical study of twenty squares boards (de Voogt, Dunn-Vaturi and Eerkens) concluded that, despite the evidence of transmission of the board across dozens of generations, thousands of miles and the use of the board by multiple cultures and languages including enemies, the board did not change much, compared to ceramics or other shared cultural characteristics in the Middle Bronze Age cultures.
de Voogt A, Dunn-Vaturi A-E, and Eerkens JW. 2013. Cultural transmission in the ancient Near East: twenty squares and fifty-eight holes. Journal of Archaeological Science 40(4):1715-1730.
Depaulis T. 2000. Les Indo-Européens jouaient-ils aux dés? Board Game Studies 3:103-106.
Dunn-Vaturi A-E. 2000. “The Monkey Race” – Remarks on Board Games Accessories. Board Game Studies 3:107-111.
Romain P. 2000. Les représentations des jeux de pions dans le Proche-Orient ancien et leur signification. Board Game Studies 3:11-38.