Double Stacks slot review

By NetEnt

Double Stacks Basic info

Game provider NetEnt

Release Date 9/2018

RTP 96.10%

Game Technology HTML5

Popularity Medium

Min bet $0.10

Max bet $200

Max Win bet x 1000

Gamble Feature Stacked symbols, Multiplier, Freespins, Scatter symbols, Volatility

Layout 5x3

Devices Support all devices

Configurable Winlines No

Volatility High

Progressive Jackpot No

Double Stacks takes the concept of the classic fruit machine and blasts it into the future with neon symbols, stacked reels and free spins!

Developed by NetEnt and released in 2018, Double Stacks jumps off the screen with its neon-coloured symbols, thumping soundtrack and selection of moderate but significant features. Using a standard 5-reel, 3-row playing field with 10 paylines the game stays close to the classic slot layout, however, keeping it relatable to players that enjoy those type of slots.

I am not a huge fan of the classic fruit machines because I think they’re usually simple and contrived, innovating very little if at all and making it difficult why to pick one of them over all the others. Double Stacks also falls into that trap but at least attempts to stand out with its crazy neon symbols.

While the symbols are still the usual fruit machine variation they are all turned up to 11, with colours that almost shone off the screen. Not only that but the entire game is designed to amplify this idea. When getting the free spins mode the reels disappear and a stylish text screen appears, flashing the letter FREE SPINS on the screen before switching to the actual feature.

Meanwhile, there is a low-energy techno song playing in the background while the reels spin. Triggering the free spins mode switches it to an upbeat tempo with a thumping bass as the free spins go. Really got the blood flowing as the wins kept stacking up!


All the symbols in the game are based on classic fruit symbols. The twist the artists gave it was the neon hue to them, making them almost literally shine. Even little details like the glow touching the textures behind them enhance the idea they’re shining bright.

The symbols are from highest to lowest:

  • Scatter: Get 3 or more on the screen at the same time to trigger the Free Spins mode. Get up to 30 free spins with 5 scatter symbols.
  • Wild: Wild symbols substitute all other symbols in the game except the Scatter Symbols.
  • Diamond: Max. 1,000 coins with ten-of-a-kind on a winning payline.
  • 7: Max. 500 coins with ten-of-a-kind on a winning payline.
  • BAR: Max. 250 coins with ten-of-a-kind on a winning payline.
  • Bell: Max. 100 coins with ten-of-a-kind on a winning payline.
  • Cherry: Max. 60 coins with nine-of-a-kind on a winning payline.
  • Plum: Max. 60 coins with nine-of-a-kind on a winning payline.
  • Lemon: Max. 60 coins with nine-of-a-kind on a winning payline.
  • Watermelon: Max. 60 coins with nine-of-a-kind on a winning payline.

A special feature that I’ll discuss later is the Double Stacks feature, which causes all stacked symbols to double up. This means they appear as two symbols on a single spot, also doubling their value.

Only the 4 highest paying symbols in the game can appear as stacked in the base game. Since Wilds can be stacked it means the fruit symbols, the lowest 4 symbols in the game, can technically have 4 reels filled with Double Stacked Wilds but have 1 reel with a single fruit symbol which is why they can only have nine-of-a-kind instead of ten-of-a-kind.

I thought all the symbols looked great. When they double up they have a small animation and getting a winning payline has the background flash. The free spins mode looks the same as the base game, unfortunately.


Double Stacks doesn’t have a crazy number of features but there’s enough of them to shake up the classic fruit machine experience. In short, they are:

  • Wilds: Wilds appear on the screen and substitute all other symbols in the game except the Scatter Symbols.
  • Stacked Symbols: During the base game, the 4 highest-paying symbols can appear stacked to fill the reel.
  • Double Stacks: When a symbol appears stacked, it will automatically double itself. This means they will count as 2 symbols on a winning payline. Wilds can also be Double Stacked while in free spins mode.
  • Free Spins: Getting 3 or more Scatter symbols on the screen at the same time will trigger the free spins mode. When this happens, Stacked Wilds can appear in this mode. Getting 3 Scatter Symbols will grant 5 free spins. Additional free spins can be earned during the Free Spins mode.

The main feature in the game is obviously the Double Stacked feature. This one pops up very frequently, almost every spin in my experience. Obviously this doesn’t mean there is always a win but their regular appearance makes a larger win more likely. The listed High Volatility definitely rings true, however. Even with the Double Stacks, the game goes through your funds very quickly and it only rarely pays off.

I started playing this slot with a small bet per spin with the idea to increase it as I got a grip on how often it pays out, but I kept it small the entire time because I didn’t feel like it was worth it investing heavily. Even though the prospect of a max. win of 1,000x your bet is appealing, I felt it wasn’t quite balanced with the volatility. Luckily, the game allowed me to choose a bet between $0.10 and $200 per spin which gave a lot of wiggle room.


As far as fruit machines go, NetEnt’s Double Stacks goes a long way in making it interesting for players like me. While the core gameplay sticks very close to what everyone is familiar with, the flashy looks and the added features help in keeping it interesting.

If you’re looking for a classic type slot that doesn’t stray as far from the base concept I would recommend something like Playson’s Mega Burning Wins or Inferno Star by Play ‘n GO. These slots are not as interesting to people like me, but probably appeal more to those that are looking for a classic slot experience.

I really liked the neon look of this slot and I played it longer than I probably had to just to enjoy the visuals. It is flashy and over the top and I must say I would like to see more slots deploy this type of aesthetic. The sound stayed a little too much on the background for my taste, I think a bolder and louder techno beat might have elevated the slot just a little bit more.

Leticia Miranda

Leticia Miranda

Slot Games Analyst

Leticia Miranda is a former gambling reporter who knows everything about slot games and is happy to share her knowledge. She has covered a broad swath of topics and trends on gambling and is always full of new ideas and energy. Leticia also has a master’s degree in journalism from New York University and is passionate about writing.