Well, think I mentioned this ages ago, but when we were in South Africa & visited an iron age settlement at Mapungubwe, there was a stone with very cupmark things on it which the guide said was a gaming board....
One of the megalithic stones has a pattern that has much simularity with the Roman gameboard. Don't know offhand which one though, I've got an example somewhere.
Wouldn't it be great if we could show that all of that rock art was gaming stuff. That would prick the bubble of those who declare that everything that we don't understand must have a "ritual purpose". Obvious really - shepherds played tiddly winks and shove ha'penny when the livestock was safely tucked up in the henge corrals.