Ask HN: Are lottery random-picked numbers truly random?

With all of the latest national buzz on the lottery, a thought crossed my mind: how are random numbers generated by lottery registers? Are they done locally on the machine itself, or do they make a request to some external service? Does each store get assigned a subset of number ranges (think subnet masks with IP addresses) to choose from, or is every machine regardless of store/location free to select from all possible numbers?