This is the relevant reference from the Books where Stone Toss is mentioned.
I make no pronouncements on these matters, but report them as I find them.
Arrive at your own conclusions.
I wish you well,
The children that we passed in the streets, playing at marbles or stone toss, scarcely glanced up.
. . .
The boy who had struck her, I believe, had been in a fit of ill temper. I think he had just lost at stone toss.
Guardsman of Gor Book 16 Page 197