Due to some rather archaic laws surrounding gambling, you will often hear of some weird and wonderful ways that slot machine designers and developers have tried to circumvent gambling laws regarding the operation of their slot machines.
Take for example over in Virginia in the U.S., that state once had strict laws surrounding gambling and slot machines were not allowed to be legally operated within the state boundaries, however operators of gaming machines realised that be adding a unique feature to their slots they were able to get around the laws.
That was to introduce an element of skill to such machines, which would usually involve a player tapping on the slot machines screen to stop the third reel spinning, or tapping on a symbol to turn that symbol wild, in the hope that by doing so they manged to complete a winning combination, based on where they managed to stop that reel or which reel symbol they chose to turn wild.
However, the laws in Virginia have been changed, and nowadays slot machines are appearing all over that state in gas stations and convenience stores too.
One very unusual feature though regarding the way those now legal slot machines must operate is that they do not use the much more standard random number generators that slot machines the world over tend to use to determine their outcomes.
Instead the results of old horse races are used to determine the outcome of each spin played off, and players can often see the old horse races being replayed on the screen of the slot machine they are playing.
As such, if you are looking for a very unusual slot machine playing experience, then I suggest if you are ever in that part of the world, you make a point of playing some of the 2000+ slot machines that can be found all over the state of Virginia, as you may enjoy playing them.