Sizing up "Can random number generator be fixed?" takes one look at the draw. Keno, bingo and scratch cards are the number games that sit closest to a lottery. Each one draws or reveals numbers at random, pays by a fixed table and asks nothing of the player beyond a choice of numbers or a ticket. What they pay, whether they can be rigged and how they work online explains why they are popular and why they cost more than they appear to.
Online scratch cards work differently from printed ones: each card is generated at the moment it is bought, from a random number generator with a published return. Anyone can play scratch cards online where the site is licensed, and winnings go straight to the account. Printed winning cards can usually be cashed at any retailer that sells that lottery's tickets up to a set amount, but not anywhere else, and larger prizes are claimed from the lottery itself.
Lottery scratch cards work from a print run whose number of winning tickets is fixed before any card is sold. Each card is printed as a winner or a loser; scratching only reveals which. They are not rigged in the sense of changing results, but the odds are set in advance and printed on the back or on the lottery's site, and many prizes simply return the price of the ticket. Buying late in a run changes nothing a buyer can see.
Which numbers are chosen makes no difference; how many spots are picked changes the pay table and the odds, and birthdays are as good as any.
Bingo prizes are paid from card sales minus the operator's share, so more players in a session mean bigger prizes and longer odds for each card.
Keno keeps among the highest edges in any casino, often twenty percent or more, which makes it better suited to small stakes and patience.
Smaller prizes are usually paid at any retailer selling that lottery's tickets up to a set amount, while larger wins are claimed from the lottery itself.