Bonanza Slot Review: The Game That Invented Megaways

The studio behind it, Big Time Gaming, is an Australian developer that spent years as a respected but mid-sized supplier before Bonanza turned it into one of the most influential names in the business. The Megaways patent it created became so valuable that Big Time Gaming licensed the engine to dozens of other studios, and in 2021 the company was acquired by Evolution, the live casino giant, in a deal that valued its intellectual property in the hundreds of millions. When you load Bonanza, you are playing the machine that started all of it. If you want a plain-language primer on the mechanics discussed here before you spin, our team at the leading USA online slots guide keeps explainers for every feature named in this review.

This review covers the two titles that carry the Bonanza name in a form built for online play: the original Bonanza and Bonanza Megapays, the 2021 sequel that bolts a four-tier progressive jackpot onto the same engine. Both are online games. Big Time Gaming does not build physical casino cabinets, so there is no land-based version of Bonanza sitting on a Las Vegas floor. Below you will find a flagship spec sheet, a full version comparison, a symbol and bonus breakdown, an honest read on how the unlimited multiplier actually behaves, and guidance on where the game can be played in the United States regulated market right now.

Bonanza quick-view table (flagship title)

Version comparison table

The studio and why Bonanza became a hit

Big Time Gaming was founded in Sydney in 2011 by industry veterans Nik Robinson, Huw McIntosh and Ian Schmidt, names that had already spent decades building slot content for major suppliers. The studio built a reputation for clever, math-forward games before it changed the industry with a single idea. That idea was Megaways, a reel system that stops using a fixed grid and instead loads a random number of symbols, between 2 and 7, onto each of the six reels every spin. When all six reels come in tall, the game reaches its ceiling of 117,649 ways to win. Bonanza was the game chosen to introduce it to the world, and it launched on December 7, 2016.

The reason Bonanza became a hit is a mix of novelty and genuinely good design. The Megaways engine felt fresh because nothing else played like it, and the gold mining theme gave the mechanic a natural home. Symbols do not just sit on reels here, they arrive in a rolling mine cart above the grid and explode out of dynamite. Wins clear away and let new symbols cascade down, which Big Time Gaming brands as Reactions, and each consecutive winning Reaction pushes a multiplier higher. In the free spins that multiplier has no cap, which is the single feature players talk about most. A hot session where the reels keep reacting can stack a multiplier into double or triple digits, turning a modest line into a life-changing hit. To see how this format sits next to every other mechanic in the market, our Megaways slots hub is the place to start.

The commercial impact was enormous. Rather than keep Megaways to itself, Big Time Gaming licensed the engine to other studios, and names such as Blueprint Gaming, Red Tiger, Pragmatic Play and many more paid to build their own Megaways titles. That licensing business turned an independent Australian developer into an acquisition target, and in 2021 Evolution completed a purchase of the studio. Every time you see the Megaways badge on a slot from any provider, you are looking at the legacy of the engine that debuted inside Bonanza.

Game overview and how it plays

Bonanza is a ways-based slot rather than a payline slot. Winning combinations form when matching symbols land on adjacent reels starting from the leftmost reel, in any row position, and only the leftmost-to-rightmost run counts. What makes it different from a standard ways game is that the height of each reel changes every spin. On a given spin one reel might show 2 symbols and the next might show 7, and the total number of ways is the product of all six reel heights. When every reel lands at its tallest, 7 symbols each, the math produces 117,649 ways. That is where the Megaways name comes from, and it is why the ways count on screen jumps around wildly between spins.

Above the six main reels sits a horizontal cart reel that scrolls its own set of symbols across the top. This top reel feeds extra symbols into the four center reels, reels 2, 3, 4 and 5, effectively adding a seventh row to those reels and widening the ways count further. The wild, a stick of dynamite, only ever appears on this top cart reel, so wild substitutions always come from above the grid rather than from the main reels themselves. It is a distinctive layout that has been copied countless times since, but Bonanza did it first.

The engine that drives the excitement is Reactions, Big Time Gaming’s name for cascading reels. When you land a winning combination, those symbols explode and disappear, and new symbols drop down or roll in from the cart to fill the gaps. If the new arrangement creates another win, it pays and reacts again, and this can chain several times from a single paid spin. In the base game each Reaction is straightforward, but in the free spins each consecutive Reaction lifts a multiplier by 1, and that multiplier does not reset until the feature ends. Because Bonanza is a high volatility game, the base spins are lean by design. Long stretches can pass with little return, and the meaningful money is locked behind the free spins and the multiplier that builds there. If high variance is a new idea, our volatility guide explains what a session on a game like this actually feels like.

Symbols and what they pay

Bonanza uses a two-tier symbol set that fits the mining theme. The premium symbols are four colored gemstones, a green, a blue, a purple and a red gem, with the highest gem paying 50x the stake for a run of 6 across the reels. The lower tier is made up of stylized card ranks, the 9, 10, jack, queen, king and ace, which fill the reels and pay small amounts. The dynamite is the wild and the gold letters are the scatters. Exact per-symbol pay tables can vary slightly between operator builds, so the table below describes rank order and the confirmed top award rather than inventing multipliers for every tier.

Bonus symbol cross-check across versions

Both versions in the family share the same core bonus grammar, which keeps the brand consistent between the original and the jackpot sequel. In each case the scatter is represented by the gold letter symbols that spell GOLD across the center reels, and landing all 4 is what unlocks the free spins. In each case the wild is the dynamite that appears only on the top horizontal cart reel and substitutes for every paying symbol but not the scatter. Neither version swaps the scatter for a different bonus symbol, and the dynamite wild never doubles as the scatter in either build. The one meaningful difference is that Bonanza Megapays adds an extra layer of special symbols on top of this shared foundation. The jackpot version introduces gold coin symbols that carry cash values and jackpot markers, and it is those coin symbols, not the GOLD scatters, that drive the Megapays progressive jackpot feature. So the free spins trigger symbol is identical across both games, while Megapays layers a second, separate jackpot symbol set that the original does not have.

How to trigger the bonus

In Bonanza the free spins round is triggered by landing 4 or more scatter symbols, the gold letters, across the reels. The scatters land on the four center reels, and collecting the full set awards 12 free spins to start. Any additional scatter that lands on the triggering spin adds 5 more free spins to the opening total, so it is possible to begin the round with more than the base 12. The trigger is the same in Bonanza Megapays, which also hands out 12 free spins for 4 scatters. Because the scatters only need to appear on the center reels and the reels can grow tall, the trigger is reachable but still demands patience given the high volatility.

How the bonus works

The free spins round is the heart of both Bonanza games, and it is where the game earns its reputation. Once you land your 4 scatters and the 12 free spins begin, the setting shifts to an underground mine and the defining feature switches on: the unlimited multiplier. It starts at 1x. Every time a spin produces a winning Reaction, the multiplier climbs by 1, and crucially it does not reset between spins for the entire length of the feature. In the base game each cascade is independent, but in the free spins the multiplier is persistent and cumulative. String together a run of consecutive Reactions and the multiplier can climb into the tens or even hundreds, and because there is no cap, a single well-timed line late in a hot feature is what produces Bonanza’s biggest results. This is the mechanic the whole industry copied.

Extra free spins can be won two ways once the round is running. Landing more gold scatters during the feature adds 5 spins each, exactly as on the trigger. Separately, the mine cart above the reels carries gold bars, and collecting them during the feature awards more spins, with 3 gold bars giving 5 additional free spins and 4 gold bars giving 10. Between the retriggers and the bar collection, a feature that stays hot can extend well past its opening 12 spins, and every extra spin is another chance for the persistent multiplier to climb higher. Because the multiplier never falls back to 1x mid-feature, the longer the round lasts, the more dangerous it becomes in the best sense.

Bonanza Megapays plays the free spins the same way, with the same unlimited multiplier, but it adds a second bonus on top. The Megapays jackpot is driven by gold coin symbols that carry cash values. When enough of these coins land and lock across the grid, they can award one of four progressive jackpots, sized by how many coins are collected. The Megapays feature is de-risked and municipal, meaning the jackpots are funded from a shared pool that grows across every player and every casino running the game until someone hits. This progressive layer sits alongside the free spins rather than replacing them, so a Megapays session can pay through the multiplier, through the jackpot coins, or both.

Version by version

Bonanza

The original Bonanza launched on December 7, 2016, developed and published by Big Time Gaming, and it is the game that introduced the Megaways engine to the world. It set the template the entire format follows: 6 reels with a random 2 to 7 symbols each, a horizontal cart reel feeding the four center reels, up to 117,649 ways to win, dynamite wilds that only appear on the top reel, gold letter scatters that trigger the bonus, and Reactions cascading reels that build an unlimited multiplier during free spins. The reported RTP sits at 96 percent, right around the online average, and the volatility is high. Bet sizing on the common build runs from 0.20 up to 20 per spin, though the range varies by operator and some high-roller builds allow much larger stakes.

Bonanza is an online-only game. Big Time Gaming has never built physical casino cabinets, so there is no land-based Bonanza machine on a Las Vegas or tribal casino floor. In the United States regulated online market, Bonanza reaches players through the Evolution content network, since Evolution now owns Big Time Gaming and distributes its slots to licensed operators. Availability is strongest in New Jersey, where lobby scans have shown Bonanza live at operators that carry the Evolution and Big Time Gaming catalog, and it can appear in other regulated states as suppliers expand. Because online lobbies rotate titles, the honest guidance is to confirm the game inside a licensed client before assuming it is present. The maximum win is commonly published at 12,000x the stake, though some review sources list a higher ceiling of around 26,000x, a reflection of just how far the uncapped free spins multiplier can stretch a single result.

Bonanza Megapays

Bonanza Megapays arrived on June 7, 2021, again developed by Big Time Gaming, and it landed the same year Evolution acquired the studio. It is a remaster and expansion of the original rather than a full reinvention. The core engine is unchanged: 6 reels, up to 117,649 ways, the dynamite wild on the top cart reel, the gold scatters, Reactions cascades, and the same unlimited multiplier in a 12 free spins round triggered by 4 scatters. What Megapays adds is the patented Megapays progressive jackpot, a four-tier system built into the base game. Gold coin symbols carry cash values and, when collected in sufficient numbers, award one of four jackpots that grow the deeper the collection goes.

The four tiers are seeded at rising amounts, with a Mini and Midi tier for smaller collections, a Major tier for larger ones, and a Mega tier that seeds around 300,000 in the base currency and climbs from there as it goes unclaimed. Big Time Gaming has promoted the Mega jackpot as capable of paying more than 3,000,000x a small stake in the most extreme outcome, a headline figure that reflects the shared, ever-growing nature of the prize pool. The reported RTP is 96.4 percent, but that figure is split, with roughly 86.96 percent returned through normal play and about 9.44 percent allocated to funding the Megapays jackpots, so a large share of the theoretical return is locked inside the progressive feature. The base-game maximum win remains 12,000x the stake, with the jackpots layered separately on top. Bets run from 0.20 to 30 per spin. Like the original, Megapays is online-only with no land-based cabinet, and because it carries real-money progressive jackpots its availability in specific US regulated lobbies can be more limited than the original, so verifying it inside a licensed client is especially worthwhile.

Which Bonanza version should you play

The choice between the two comes down to whether you want the pure original or the jackpot chase. The 2016 Bonanza is the cleaner expression of the concept, a 96 percent RTP game with the unlimited multiplier as its single headline feature and no distractions. Every bit of the theoretical return is available through normal play, and the max win of 12,000x, stretched further by the uncapped multiplier, is enough to keep any high-variance player engaged. If you simply want to experience the machine that started the Megaways era exactly as it was designed, the original is the one to load.

Bonanza Megapays is the pick for players who want an extra prize on the table and do not mind that some of the return is diverted to fund it. Its headline 96.4 percent RTP looks higher on paper, but with about 9.44 percent of that locked inside the Megapays jackpot pool, the base game returns closer to 87 percent, which means longer dry spells in exchange for the chance at a four-tier progressive that can dwarf the 12,000x base ceiling. It is the more modern, higher-ceiling option, but it is also the more volatile of the two in practical terms. For most players the original delivers the essential Bonanza experience, while Megapays is the version to seek out specifically when the growing jackpot is the draw. Whichever you choose, both are high variance, so bankroll discipline matters more here than on a gentle low-volatility slot.

Bonanza and the birth of Megaways

It is hard to overstate how much Bonanza changed online slots. Before December 2016 the industry ran almost entirely on fixed paylines and fixed reel grids, with 243 ways or 1,024 ways games considered the expansive end of the market. Bonanza broke that ceiling by making reel height itself random, which pushed the ways count to 117,649 and gave every spin a different shape. The idea was novel enough that Big Time Gaming patented it under the Megaways name, and that patent became one of the most valuable pieces of intellectual property in the gambling supply business.

Rather than hoard the engine, Big Time Gaming turned it into a licensing operation. Studios that wanted to build their own Megaways slots paid to use the format, and the list of licensees grew to include some of the biggest names in the industry. That is why you can find Megaways versions of established brands from many different suppliers, all of them descended from the framework that debuted inside Bonanza. When Evolution acquired Big Time Gaming in 2021, the Megaways licensing business was a central reason for the deal, cementing Bonanza’s status as not just a popular slot but a foundational one. Nearly a decade on, the Megaways badge remains a genuine selling point, and it all started with a gold mine.

Mobile play

Both Bonanza games were built in HTML5 and run in a mobile browser without a separate download, and Bonanza Megapays in particular was designed for full-screen portrait play on a phone. The reels stay legible on a small screen, the rolling cart and exploding dynamite animate smoothly, and the tap-to-spin and autoplay controls make the longer high-variance sessions these games encourage easier to manage on the go. Because the ways count and the free spins multiplier update constantly, a stable connection helps keep the Reactions animations crisp. For a broader look at handset play and which licensed operators run the smoothest apps, see our mobile slots guide.

Where to play

If you want to chase Bonanza and the wider Big Time Gaming catalog at a licensed, regulated site, start with the operators reviewed in our legal US slot sites directory. That is also the right place to confirm current availability, because online lobbies rotate titles and a game absent one week can appear the next as Evolution expands its distribution across regulated states. Given the high variance across this family, the high volatility slots hub is a useful companion for setting expectations, and you can read more about the studio and its other releases on our Big Time Gaming page. The RTP figures cited throughout this review are explained in plain terms in our RTP guide. Always verify a game’s paytable and return figure inside the client, since operator builds can differ.

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