WMS started out in Chicago, USA, back in 1974 as Williams Electronics, Inc, but its roots can be traced back to 1943, when Harry E. Williams founded Williams Manufacturing Company. It is one of the most iconic brands in the casino industry and the company has a strong presence in both land-based and online casinos.

But it wasn't always about slot machines. The company actually started out producing pinball machines before also branching out to the coin-operated arcade video game market in 1973. The company released several successful arcade titles such as the Pong clone Paddie Ball, and later Defender and Robotron: 2084. In 1987, Williams changed its parent name to WMS Industries, Inc, WMS being short for Williams, and as the pinball industry declined WMS eventually entered the reel-spinning slot machine market in 1994.

It wasn't until 1996 however that WMS released its first casino slot machine, Reel 'em In, which was a multi-line, multi coin video slot. It was soon followed by a number of similar successfil games like Jackpot Party (still available to this day), Boom and Filthy Rich. In October 2013, WMS merged with Scientific Games, now known as SG Interactive. Today, WMS is retained as a brand of Scientific Games, along with SG, Bally and Shuffle Master.

Best known for: its classic land-based slots and for having produced some of the most iconic slots ever released.
Popular titles: Ruby Slippers, Raging Rhino, Montezuma.
Biggest confirmed payout: nothing spectacular by today's standards. Raging Rhino and Montezuma Megaways are the ones to go for in terms of potential.
Volatility: WMS offers a wide range of mathematical models, but mostly medium to high variance.
Flexible RTP: No. RTP is fixed and cannot be adjusted by operators.
Bigwinboard trust score: Medium. No fact sheets available and lacking in the communication department. However, WMS has a long history and solid reputation.
Actual RTP with 994,019 spins tracked: 95.98%.
Avg bonus frequency: 1/103.27.

Play WMS slots at a licensed casino


Ultra fast payouts
3,500+ casino games


Superb welcome bonus
Fast withdrawals


Accredited since 2016
Responsive support


WMS Slot Reviews


Just like Novomatic, WMS has stuck to its traditions by maintaining the retro look they have become known for today. The games are easy to identify due to their characteristic visuals and even the sound which is shared by multiple games.

If you're looking for innovative slots you won't find them with WMS. However, WMS games are quite unique and no other game provider offers games similar to theirs. Despite having a relatively large game cataloge, WMS are most known for their old classics like Montezuma, Raging Rhino, Bruce Lee, Ruby Slippers, Amazon Queen, Monopoly, Kronos and Zeus.

WMS slots differ in variance and while most games are medium to high variance, there are also some low variance slots on the list. While some WMS games offer great potential, they do not in general offer the kind of potential found with other game providers such as Microgaming, NetEnt and Big Time Gaming, with max wins around 5000-10,000x.

The WMS games with the highest potential are also the most popular, like Montezuma, which can retrigger multiple times with a multiplier of up to 10x locked in place. Raging Rhino is another game known for frequent retriggers and huge potential.