Bonus Features Collection Slot Bonus Features

A bonus round, triggered when a certain number of symbols such as scatters land, that runs a set number of times with no extra bet. Free spins often come with rules that favor you over the base game, such as stacking multipliers or sticky wilds, so most of the big wins in high-volatility games come from here.

When enough scatters land again during free spins and extra free spins are added. Some games allow unlimited retriggers, while others cap the number.

An enhanced version of free spins, with higher starting multipliers or more wilds than regular free spins. You get in by collecting more scatters or by using a more expensive bonus buy.

A system where the player chooses a combination of free spin count and multiplier, such as “10 spins × high multiplier” or “25 spins × low multiplier.” You can see this in games like Madame Destiny Megaways.

A feature that keeps some reels or symbols in place and respins only the rest once. Starburst, which gives a respin after an expanding wild appears, is the best-known example.

When a certain number of bonus symbols (mostly money symbols) land, those symbols lock in place and you usually get 3 respins. Each time a new symbol lands, the respins reset to 3, and when no more appear, you collect all the amounts on screen. Many games award the Grand Jackpot if you fill the entire screen. The name varies by provider: Hold & Win (Booongo, Playson, Betsoft), Hold & Hit (Spinomenal), Hold the Jackpot (Wazdan), Money Respin, and so on.

A feature that, after the reels stop, pushes a reel up or down by one position so that a winning combination or bonus symbol comes into view. Nolimit City’s xNudge and Pragmatic Play’s Power Nudge are developed versions of this.

This is a mechanic where winning symbols disappear, new symbols drop in from above to fill the gaps, and the chain continues as long as new wins keep forming. NetEnt’s Gonzo’s Quest introduced it early under the name “Avalanche,” Pragmatic Play calls it “Tumble,” BTG calls it “Reactions,” and others call it “Cascade.” A single spin can produce multiple wins.

A multiplier applied to your winnings. It comes in various forms: landing as multiplier symbols, attached to wilds, or rising with each chain. In Gates of Olympus, all multiplier orbs on screen are added together and applied to the win.

A multiplier that grows by +1 or doubles each time a chain of wins or free spins continues. An “unlimited multiplier” that does not reset until the free spins end is the core of Megaways games like Bonanza.

Positions where symbols popped from a win get marked, and when they pop again in the same spot, a multiplier appears there and keeps doubling. Pragmatic Play’s Sugar Rush is the best-known example.

Instead of paylines, a win happens when a certain number of identical symbols (usually 5 or more) connect to each other horizontally or vertically. It is mostly used together with tumbling. Reactoonz and Sugar Rush are the best-known examples.

A feature where the number of positions on the reels increases during a bonus, or the whole grid gets bigger. More positions greatly increase ways and winning chances. Elk Studios’ Pirots grows up to 8×8.

A feature where two or more adjacent reels are matched to the same image and spin as one. The same symbol appears across several reels at once, which makes big wins more likely. It is used in games such as Spinomenal’s Majestic King.

A feature where mystery symbols all change into the same symbol at once when the spin ends. If several positions turn into a high-paying symbol, it leads to a big win.

A feature that triggers without warning during a base game spin. What it does differs by game, such as adding wilds, converting symbols, or granting multipliers.

A bonus game where you pick some of the boxes, cards, or items on screen to reveal hidden prizes or multipliers.

A bonus where you spin a wheel and receive the prize, multiplier, free spins, or jackpot where it stops. It is often used to determine the jackpot in jackpot slots.

A board-game-style bonus where you move one space at a time along a board based on dice or spin results, collecting the prize or feature written on each space.

A system where a meter fills each time you collect a particular symbol, and when it is full you get a reward such as a multiplier increase or extra spins. The Big Bass series gives a retrigger and a multiplier increase each time you collect 4 fishermen during free spins.

A feature where you pay a set multiple of your bet in one go (usually around 50x to 100x) and jump straight into free spins or a bonus round. You can see the bonus with no waiting, but the cost per purchase is large. “Feature Drop” in BTG’s Extra Chilli is a well-known early example. The UK has banned bonus buy since 2019.

An option where you pay a higher bet on every spin, usually around 25% more, in exchange for a better chance of triggering free spins. Pragmatic Play’s Ante Bet, Wazdan’s Double Chance, and Nolimit City’s xBet are in the same family. In some games, turning on Ante Bet disables bonus buy.

A feature from Elk Studios that offers several choices at different prices, from modes that raise your bonus chance to modes that take you straight into a higher-tier bonus. In Pirots, the options range from 3x to 500x your bet.