Carnivals are sh*t. Chavs everywhere, expensive rigged games that you cant win and overpriced, dangerous rides. At least Simon Cowells never actually tried to kill me!!
Rides are meant to give you a feeling of danger without being dangerous, if they were dangerous then they would never get a licence to run them.
Machines dont need to be rigged against you, they are built to favour the owners chances of winning. 70% payout is generally the minimum, without it they wouldnt be able to run the place and pay the staff.
That does mean that for every £ you put in you are only going to get 70p out on average.
Gambling is a losers game, unless you are running it, exept there are plenty of fools willing to part with their money for a little excitement.