RTP, or return to player, is the percentage payout that a slot makes over a very large number of spins. UK law requires that it be displayed somewhere on the slot machine or slot site (although it is much easier to find on some sites than on others). Most online slots have an RTP of 90-95%, with the progressive ones having a lower RTP due to the contribution made towards the progressive jackpot. But what does RTP of 95% really mean?
It does NOT mean that if you deposit £100 with a slots site, you will eventually win and be able to withdraw £95.
Let’s look at why not:
1) The RTP is an average over a very large number of spins carried out by a large number of different players. Some will win big, some will win more than they lose, some will lose more than they win and some will lose their shirts – it all averages out to the slot paying out 95% overall of what was wagered.
2) The RTP is for money wagered, NOT money deposited. If you deposit £100 and start playing slots, you’d have to be very unlucky indeed not to have any money left at all after £100 worth of spins. But what will you do then? Will you withdraw and walk away? Most wouldn’t even if the casino would allow it (and wagering requirements mean most won’t) – they would just keep playing with their winnings. But once you start playing with your winnings instead of your original deposit, the RTP starts to multiply – and as it is less than 1, as it multiplies it gets smaller and smaller.
Let’s imagine you deposit £20 and play at £1 a spin – and the slot has an RTP of 90%. Your expected return from those spins is £18 (although it probably won’t actually be £18 as 20 spins is far, far too small a number to be statistically significant). You continue to play – and your expected return from the 18 spins you can now make is 90% of £18 = £16.20. So now you get to make 16 more spins, with an expected return of 90% of £16 (plus the 20p left over) = £14.20 (plus 20p). You can now make 14 more spins, and….well, you can see where this is going, can’t you? Once you have made around 100 of those £1 spins, if the RTP on those 100 spins runs close to the average you’ll have around £10 left – half of your original deposit. That’s a pretty quick way to lose £10 – possibly even quicker than the proverbial setting fire to it!
Want to play for longer? Try the same thing on a PENNY slot with a better RTP of 95% – and the picture is much rosier. The expected number of spins to lose half your £20 deposit at 1p a spin ? A whopping 21,000 spins (on a 1 line slot).