Stat rolling is not as common in TT these days. For it to be as fair a choice as other methods, you can't allow rerolling or opting out afterwards. The average of the random spread equals default array, so rerolling means other players need stat inflation, but that's a ton of math.
4D6dl = 27pt buy = default array
I've had players opt out after I've reiterated no rerolling. I've also rolled default array!
