📜 How it works
From worn stone to plausible rules
Nobody wrote down how the Ludus Coriovalli was played. So how can anyone reconstruct it? By reasoning from the one piece of evidence that survived — the wear — the same way a real 2026 research team did with a super-computer.
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Read the wear
with Coria the Reader
A stone gets rubbed smooth where the pieces travelled most. So the WORN lines are your evidence: on this stone a diagonal is heavily worn, the centre is not, and the wear spreads widely. Those three facts are the whole case-file.
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Build a rule set
with Brickwright
A game is made of small rules — a board shape, a starting layout, and a way to win. Snap those “bricks” together into one complete rule set. Change one brick and you have a different game to test.
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Wear it down
with Playra
Play your rules hundreds of times and count where the pieces travel — the board slowly “wears,” exactly like the real stone did over centuries. (The moves are random, so the board’s own shape decides which lines get used, not a clever player.)
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Score the fit
with Plausa
Compare YOUR worn board to the REAL one, line by line: did a diagonal get heavy use? Was the centre light? Did the pieces spread out? The more facts your rules fit, the more plausible they are — plausible, never proven.
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Stay honest
with Cavea
Here is the big idea: a rule set that FITS the wear is only PLAUSIBLE — not proven. A computer search “will always find some rules” that fit. So the honest answer is “this is a plausible way it may have been played,” never “this is how it was played.”
Now try it yourself
You know the method — now BE the archaeologist. Pick a board, choose how to win, and run the wear test.
🔎 Start the dig →Where this idea comes from· Crist et al., Antiquity 2026
The stone with no rulebook
A flat stone with lines cut into it, kept at Het Romeins Museum in Heerlen, the Netherlands, where the Roman town of Coriovallum stood. The museum’s records say only that it was found in Heerlen. It is white limestone from quarries at Norroy in north-eastern France, 212 × 145 × 71 mm and 3.38 kg: probably a piece of ornamental building stone, reshaped and cut into a board in the late Roman period, about AD 250–476.
One thing to hold: Object 04433. Its measurements and 3D model are free for anyone to use (CC0) on DataverseNL.
Why it matters: In 2026 Walter Crist and six colleagues ran simulated games with many sets of rules and kept the ones whose pieces wore the board the way the real stone is worn. Wear is the only evidence that survived.
What we don’t know: Where exactly it was dug up was not recorded, so the date comes from the stone, not from where it lay. And the rules are a good fit, not a proof: as Dennis Soemers put it, the computer “will always find game rules”, and “we cannot be sure that the Romans played it in precisely that way.”
Dates:
- 250–476 AD, the late Roman period, when the board was probably cut
- 2026 the simulation study is published