Features and Mechanics Overview

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Online slots have evolved tremendously over the past few decades. What started as simple 3-reel games with a single payline have transformed into complex video slots with hundreds of paylines, special features, and innovative mechanics. While classic slots still have their charm, players today gravitate toward games that offer more excitement through advanced features and greater winning potential. We will provide an in-depth look at the most notable slot mechanics and features that have redefined the slots experience.

Reel Mechanics

The reels are the beating heart of any slot game. While they were quite straightforward in vintage slots, modern slots incorporate various reel mechanics that add more dynamism to every spin.

Cascading Reels

Cascading reels

Also known as avalanche or tumbling reels, this mechanic causes winning symbols to disappear and new ones cascade down to fill the empty spots. This creates the potential for multiple wins from a single bet. Some popular cascading reel slots include:

Expanding Reels

Expanding reels

When a winning combination lands, extra reels are added to the grid, offering more chances to hit winning combos. Slots with expanding reels include:

  • Temple Tumble Megaways (Relax Gaming)
  • Gods of Gold: InfiniReels (NetEnt)
  • Buffalo Rising Megaways (Blueprint Gaming)

Splitting Reels

Splitting reels

Also called “multi-reels,” this mechanic splits the main set of reels into two or more sets. It allows gameplay and payouts across different reel sets. Examples include:

  • Twin Spin (NetEnt)
  • Multiplier Man (Wazdan)
  • Dragon Match Megaways (iSoftBet)

Walking Wilds

Walking Wilds

These are wilds that move across the reels on each spin during a feature. They create more winning potential as they walk. Slots with walking wilds:

Nudging Reels

If a winning combination is one symbol away from landing, the reels may nudge up or down to complete it. Some slots with nudging reels:

  • Razor Shark (Push Gaming)
  • Jammin’ Jars (Push Gaming)
  • Pixies vs. Pirates (Nolimit City)

Horizontal Reels

Horizontal Reels

An extra reel laid horizontally across the screen can help form wins. Often seen in Megaways slots, like:

  • White Rabbit Megaways (Big Time Gaming)
  • Buffalo Rising Megaways (Blueprint Gaming)


Most slots have multiplier features that can dramatically increase payouts. Here are some types:

  • Standard multipliers apply a set value like 2x or 5x to wins.
  • Progressive multipliers increase with each winning spin, like 2x, 3x, 5x etc.
  • Rolling reels multipliers apply a multiplier, then increase it if you land a subsequent win.
  • Sticky multipliers remain in place over multiple spins during features.

Examples of slots with great multiplier features:

  • Book of Dead (Play’n GO)
  • Reactoonz (Play’n GO)
  • Legacy of Dead (Play’n GO)
  • Bonanza (Big Time Gaming)

Win Mechanics

While classic slots offered fixed paylines, modern slots incorporate dynamic and diverse mechanics for landing winning combinations.

243 Ways

243 ways to win

Pays for adjacent symbol matches from left to right across a 5×3 grid. No paylines. Some 243 Ways slots:

1024 Ways

1024 ways to win

Functions like 243 Ways but with a 5×4 grid for more pay combos. 1024 Ways slots include:

  • Jaguar Princess (High 5)
  • Blazing Goddess (High 5)
  • Cash-O-Matic (NetEnt)



Slots with the Megaways engine have a random number of symbols per reel, allowing 100,000+ winning combos. Popular Megaways slots:

Multiway Xtra

This mechanic pays for non-adjacent symbol matches. It dramatically increases the pay combos. Examples include:

  • Raging Rhino (WMS)
  • Jackpot Jungle (WMS)
  • Black Knight II (WMS)

Cluster Pays

Cluster Pays

Wins are awarded for clusters of adjacent matching symbols, not paylines. Some cluster play slots:

Win Both Ways

both way win

Gets paid for symbol matches from left to right AND right to left. These slots include:

Cash Respin

After a winning combo, a respin occurs with a chance to win again. Examples:

  • Money Train (Relax Gaming)
  • Bonus Train Bandits (Booming Games)
  • Cash Eruption (Greentube)

Locked Reels/Held Reels

After a win, the winning symbols are locked while the rest of the reels respin for more potential wins. Some slots with locked reels:

  • Rise of Olympus (Play’n GO)
  • Legacy of Egypt (Play’n GO)
  • Book of Oz (Microgaming)

Special Symbols

In addition to innovative reels and wins mechanics, modern video slots incorporate a slew of unique symbols and bonus features. These elements add surprise, engagement, and big win potential. Here are some key examples:

Expanding Symbols

Expanding Wilds

When this symbol lands, it expands to cover an entire reel for bigger wins. Some slots with expanding symbols:

Stacked Symbols

Multiple instances of a symbol stacked on a reel. Creates more chances for big wins. Some slots with stacked symbols:

  • Money Train 2 (Relax Gaming)
  • Legacy of Dead (Play’n GO)
  • Book of Ra Deluxe (Greentube)

Sticky Wilds

Sticky Wilds

Wilds that remain in place over multiple spins during features. Found in slots like:

Scatter Symbols

Scatters pay out anywhere on the reels. They also trigger free spins and bonus features. Some top slots with scatters:

  • Book of Dead (Play’n GO)
  • Legacy of Dead (Play’n GO)
  • Reactoonz (Play’n GO)
  • Jammin’ Jars (Push Gaming)

Mystery Symbols

These can transform into other symbols, including high-win ones, for surprise payouts. Examples:

  • Rise of Olympia (Play’n GO)
  • Ozwin’s Jackpots (Blueprint Gaming)
  • The Goonies (Blueprint Gaming)

Split Symbols

Can split into multiple symbols for bigger wins. See in slots like:

  • Temple of Nudges (Microgaming)
  • Relic Seekers (Pragmatic Play)
  • Syncronite Splitz (Yggdrasil)

Special Features

Bonus Buy

Lets you buy direct entry into a bonus round. Popular in Megaways slots like:

  • Bonanza (Big Time Gaming)
  • Legacy of Dead (Play’n GO)
  • Buffalo Rising Megaways (Blueprint Gaming)


Progressive and stand-alone jackpots seed prizes that can grow into millions. Top jackpot slots:

  • Mega Moolah (Microgaming)
  • Divine Fortune (NetEnt)
  • Mega Jackpots Cleopatra (IGT)
  • Mega Jackpots Siberian Storm (IGT)

Free Spins

Awarded through scatters and bonuses. Provide spins at no cost that can lead to big wins. All top slots have great free spins bonuses, like:

  • Book of Dead (Play’n GO)
  • Legacy of Dead (Play’n GO)
  • Jammin’ Jars (Push Gaming)
  • Reactoonz (Play’n GO)

Pick Bonuses

Let you select from hidden prizes like free spins, multipliers, and cash rewards. Examples:

  • Legacy of Dead (Play’n GO)
  • Solar Queen (Play’n GO)
  • Rise of Olympus (Play’n GO)

Reel Modifiers

Random added features like extra wilds, multipliers, removed symbols etc. Found in games like:

  • Fat Rabbit (Push Gaming)
  • Jammin’ Jars (Push Gaming)
  • Extra Chilli Megaways (Big Time Gaming)

As shown, modern slots incorporate a diverse range of mechanics and features that dramatically expand the gameplay possibilities compared to vintage slots. These elements inject more action, surprise, and winning potential into every spin. With software providers continually innovating, slots are only becoming more dynamic and engaging.

Online slots have come an incredibly long way over a relatively short period of time. Classic slots offered a simple but addictive style of gameplay based on spinning reels and payline matches. But as slots made the transition online, developers had the freedom to take the game experience to the next level through advanced mechanics, symbols, bonus events and interactive features.

While vintage slots still have their appeal, players today are captivated by games that provide an immersive, cinematic experience and the chance for epic wins. Slot studios compete to develop reel innovations, win mechanics and special symbols that make their games stand out. Popular features like Megaways, cascading reels, and locked wilds breathe new life into slot play, while jackpots seed life-changing prizes.

The result is an extensive catalogue of slots that cater to all tastes, whether players prefer classic gameplay or want more modern action. The diversity provides more ways to win, more player engagement, and ultimately, more big payout potential. Slots have been transformed into a multi-sensory digital experience with game features that simply wouldn’t have been possible on a land-based machine. As software capabilities and creativity expands, we can expect online slots to become even more feature-rich and immersive in the years ahead.