The Return to Player (RTP) is the amount a slot machine pays its users for each unit wagered over time. It is usually expressed by a percentage value and is almost always less than 100%. The difference between 100% and the slot machine’s RTP is known as the house edge, and this is the mathematical advantage that allows casinos to make profits in the long run. Slot Machines with an RTP percentage closer to 100% are often referred to as loose Slots, while games with a low RTP are referred to as tight.
For example, if you are playing a Slot Machine with an RTP value of 95%, the house edge equals 5%. This means that on average and with of millions of spins the machine wins 5% of each unit wagered.
Of course, a game that accepted a $1 bet and paid a $0.95 “win” on each spin would be horribly boring, not to mention impossible for a player to win against the machine. Thus, slots are designed with pay tables that give players a chance to win in the short term, while their operators continue to bank profits in the long term through a large player base.
A player, by choosing a high RTP or a loose Slot (or at least avoiding the low RTPs), will extend his playing sessions over the long term, so that he can enjoy more spins for his budget and get better value for his money.