[yetanotherloser]

That's interesting, I thought the case made for oracular use when I read about it was reasonable, but I may be a bit put of date. There was a fair bit of weird belief washing around in later Roman times before Christianity won out, though.

As for game rules - we have a tiny enough fraction of all non-elite-literary writing from antiquity that we probably wouldn't have a complete game's rules if they had been in the habit of writing them down - but we have so many surviving bits of writing that we ought to have fragments of rules. They seem rather thin on the ground, which leads me to suspect that written rules just didn't seem that important to most Romans. From Vindolanda to Oxyrhynchus they wrote bills and doggerel and love-life complaints and demands for new socks... but nothing at all that attempts to explain THAC0.

We don't even really know how they played Ludus Latrunculorum, despite finding quite a few sets and more boards - but there are several reconstructions from literary references. One of them I find quite engaging, so I hope it's on the right track.