I posted another thread called something like “Slots and gambles, the rules” where I posted answers direct from the Gambling Commission to questions I asked them and the gist is while the fundamental outcome of a bet (i.e. spin costing money) on online slots has to be random, anything and everything else can be programmed or pre-determined, or random, or whatever else the licensed manufacturer sees fit, provided the customer is not “misled” about their chances of winning. There is an additional stipulation that skill-based elements such as prizes hidden on a map cannot have their locations changed during play and another that losing spins cannot be artificially substituted for “near misses”. Other than that the rules are surprisingly slack.