Online slots that are regulated by any of the following: United Kingdom Gambling Commission,Malta Gaming Authority, Alderney Gambling Control Commission would all be random if the casino is abiding by the regulations set forth by the gambling authority in question. The reason I know this is because my mate made a freedom of information request to UKGC.
The way slots traditionally worked ( I’e one armed bandits etc) was there was one line and it was attached to a random number generator that is changing multiple times a millisecond, when you click spin it stops it at one of the pre-set outcomes attached to the number that it stops at on the random number generator, if that makes sense?
On video slots with 20 lines, for example, it can work in two different ways each row could have it’s own number on the random number generator assigned to it, or each line could.
The only way I can see that a casino could change the RTP is to remove more of the winning possibilities from the random number generator.
However, the RTP is pre-set by the regulatory authority that is assigned to that casino/slot so changing it would be illegal.
Not sure if I explained that very well but that’s what the casino and gambling authorities should legally be abiding by.
Also games are hosted on the server of the game provider and not the casino themselves so the casino should have no control over the RTP.
However, there was a case of a casino tropicana casino I think? That got done for fraudulently hosting some Netent games on their own server.
rowan