While machine and online slots are completely random when it comes to rewarding prizes, some slots pay out significantly more than others. This distinction is determined by the RTP (return to player) rate that each slot has programmed into it.

The RTP rate of a slot is the amount of money the game receives that is returned to players through winnings. Games with a higher RTP amount pay out more (or pay higher jackpots) than those with lower RTP rates.

While physical slot machines have an average RTP range of between 70% and 90%, online slots are much more generous. They average an RTP of around 93% to 97%, with some games offering insane RTPs of 99%.

Sadly, while these high RTP rates are the average, there are online slots that have somewhat laughable return rates. To help you identify these, we’ve gathered a list of online slots that offer the worst RTP rates – and ones that you might want to avoid.

Frankenstein – 70% RTP

Released by NetEnt, this game has an advertised RTP of a decent enough 96.7%. For a game that offers expanding wilds that can lead to a relatively great win this is a perfectly acceptable RTP. However, this is only attainable should you play on the maximum bet.

If you are playing using a low or average bet like most people, the RTP offered by the game drops to just 70%. This is easily the worst RTP of any online slot and is even in the bottom range for most physical slot machines. Sadly, the free spin bonus isn’t even exciting enough to justify the low RTP for this game.

Atlantis – 71.9% RTP

Developed by Concept Gaming, Atlantis is famous for having one of the highest RTPs available. This is thanks to the advertised 98.1% RTP. However, many casinos fail to mention that this RTP can only be gained if you play the slot on maximum bet.

If you are playing the game using the standard bet amount of $0.05 per spin, typical for most casual players, the RTP offered drops to a dismal 71.9%. This drop makes the game themed after the lost city one of the worst RTP games available today.

Slot Monsters – 71.9% RTP

Also offered by Concept Gaming, Slot Monsters is yet another slot that appears to provide an outstanding RTP of 98.1% at first glance. The sad truth is that, like the slot games above, this fantastic RTP is only attainable if you play on the maximum bet at $100 per spin.

If you play with the standard bet amount set, the RTP you’ll be offered will drop to 71.9%. This massive drop leaves you with a severely diminished chance of winning despite the progressive jackpot and bonus feature that offers win multipliers.

Eternal Desire – 80% RTP

From developer Zeus Play comes this fascinating slot with an advertised RTP of 94%. Based on Dracula, themed to show dark castles and the famed vampire himself, this slot is only worth the effort if you are playing on max bet.

If you are playing using a more typical bet, you will be saving big on your cost per spin. However, you will also drop the game’s RTP from the acceptable 94% to a much less exciting 80%. This may be hard to overlook regardless of whether you’re lucky enough to get the free spins bonus.

Mega Joker – 85.28% RTP

Available in 2011, this game by iconic developer NetEnt is well known for its insane 99% RTP. However, like the other slots on this list, this RTP is only attainable if you are playing on a maximum bet. If you choose a more casual way to play by selecting the lower bet options, the RTP changes to 85.28%.

The game tries to make up for this disappointing RTP with a feature called Supermeter. This is a new take on the traditional gamble option offered by many slots. While it makes the game more fun and interesting to play, it doesn’t quite make up for the lower RTP.

Some online slot machine games have laughably low RTPs

Treasure Box Kingdom – 86.86% RTP

Released by IGT (International Game Technology), Treasure Box Kingdom appears to have it all. From the Coin Symbol bonus that triggers a respin feature that holds specific symbols to the scatter-free spin bonus round, the game sounds great. What makes it sound even better is the 96.02% advertised RTP.

Sadly, like the other slots on this list, this generous RTP is only offered if you’re playing on the most expensive spin option. Should you be playing with a regular bet like most players, the RTP provided by the game is only 86.86%. This is significantly less and makes the game lose some of its appeal.

Mega Moolah – 88.12% RTP

While you may be surprised to see this iconic slot on this list, Mega Moolah only has an RTP of 88.12%. This is much less than thousands of other online slots and is more in line with brick-and-mortar casino games. However, this is the one slot that may still be worth playing regardless.

This risk is acceptable thanks to the insane jackpots that this progressive slot has proven it can pay over the years. The biggest of these was a staggering $19.77 million in 2018. Be careful, though; while the jackpot can be staggering, the RTP of the game proves that it may not pay out as much as other slots.

Conclusion

All the slots listed above appear fantastic at first glance, especially with their great RTP rates that are widely advertised. However, it is always best to do in-depth research to see the actual RTP of a game if you’re not playing on a maximum bet. That way, you’ll get the most bang for your buck.