Modern slot and pokie games have several key mechanics, from scatters to cash collects. Wilds are a staple, and their variations such as walking, expanding and stacked can create interesting features when combined with other concepts.
The wild is a symbol in a pokie game that substitutes for other paying symbols. Need three lemons in a row to win, but only have two? A wild on the end would act as a yellow citrus fruit, allowing you to win. In modern slots, wilds have become much more complex, adding in-depth gameplay to the old concept of reels and paylines. Walking, expanding and stacked wilds all operate differently, giving a different impact and feel to titles.
The Impact of Wilds on Volatility
The type of wilds, and how they are used within a game, can have a huge impact on how volatility works. This is a measure of how a game pays out, but does not define how much it pays out in total.
Volatility measures the pattern of payouts, not the total return. A low volatility pokie like Starburst by NetEnt pays small, frequent wins with a hit frequency of around 1 in 3 spins. A high volatility title like Dead or Alive II can go dozens of spins without a win, but its bonus round has hit for over 100,000x the stake. Understanding this pattern helps you match a game to your bankroll and play style, regardless of its RTP.
Using different wilds can cause huge changes in volatility and is down to developers’ preference. VoltRush.com lists this information directly on every pokie game page, so you don’t have to dig for it. Alongside each title you’ll find its return to player rating, which measures how much is paid back to players, and its volatility level, giving you a quick read on a game’s risk profile before you spin.
Walking Wilds
Walking wilds are named as such, as they tend to roam across the playfield. With each spin, they will generally move from left to right, or right to left. This provides an element of built-in value for players, as it can retrigger features like respins as long as they remain on the screen. In doing so, games of this nature tend to provide steady levels of volatility, with long playtimes.
NetEnt, one of the suppliers available on VoltRush, pioneered this concept in the fairytale-themed pokie Jack and the Beanstalk. Wilds will randomly appear on reels two to five and will also give a free respin. The wild will then travel, or walk, one reel to the left. This is then combined with treasure chest scatters and a key collection feature, providing a much more complex level of gameplay.
Expanding Wilds
Expanding wilds have become a very popular feature in modern pokies. The idea is that they expand to cover more sections of the reels. Typically, they will move vertically, but other games employ them in different ways, especially ones that also use cluster mechanics.
By doing this, what seems like a fairly trivial board can quickly have multiple paylines on different reels. They typically accompany games that have high volatility levels, in which an expanding reel lands and huge payouts arrive, but there are very few payouts between them.
One of the most famous pokies with expanding wilds is the ‘Book of’ series, of which Book of Dead was the pioneer. It is a good one to try expanding reels out on, as they are the main feature here. As they grow across the reels, you can make more wins, yet it also becomes the trigger for the free spins round in the game.
Stacked Wilds
Stacked wilds arrive in blocks, standing atop one another. You may find two, three or even more mounting up, providing more chances to create winning paylines. They differ from expanding wilds as they do not cover multiple reels, but just exist in a single column. This can, however, provide wins from different places, depending on the game’s rules. They are often used in games that pay out using cluster mechanics.
A good example lies in Wolf Gold by Pragmatic Play, which carries a certified RTP of 96.01% and sits at medium-high volatility. The wolf wild substitutes for all symbols except scatters and the moon bonus, and when a full stacked column lands, which happens roughly once every 150 to 200 spins based on published hit-rate data, it can trigger multiple simultaneous paylines in a single spin, spiking win frequency well above the game’s base average.
Wilds in Pokie Game Development
Wilds are now a key feature of slot game development. This is a genre that has been evolving for some time, or at least since the 1800s. The developer 1Spin4Win defines their key evolutions in the field using the table below, which is found in their Slot Game Developments and Key Insights Market Trends.
| Traditional Slots | Online Slots | |
| Age | Late 1800s with invention of the Liberty Bell machine | 1990s |
| Availability | Land based casinos, pubs and social spaces | Online casinos through devices and smartphones |
| Hardware/Software | Physical cabinets | Cross-platform compatibility programming languages like HTML |
| Number of players | One per machine | No limit |
They then go on to describe the key features that have shaped more modern pokie game development. Many of these are combined with wilds to develop complex games. This includes:
- Wilds
- Paylines
- Scatters
- Free Spins
- Multipliers
- Progressive jackpots
- Bonus Rounds
- Cascading Reels
Yet wilds are no longer just an added feature. They have been used to shape whole games and their development. Irina Cornides is the Chief Operating Officer at the Major Developer Pragmatic Play. In an August 2024 statement given to iGamingbusiness.com, regarding their new title Forging Wilds, she noted that “Forging Wilds adds a new dimension to Pragmatic Play’s extensive and diverse range of slots, firing up sticky wilds with incrementing multipliers, free respins and wins of up to 10,000x the bet.”
When you think back to the early days of pokies, in their three-reel format, they were quite simple. With fruits, lucky 7 symbols and bars, they seemed quite limited. Yet the digital era has opened up new possibilities. In this, symbols like wilds and scatters are not an addition. They have become symbols just as ubiquitous as those early melons and cherries on the mechanical reels.
Now, developers are starting to play with this concept within ideas like cluster pays and Megaways mechanics. Just as early pioneers broke the reel format and reimagined it, wilds are doing the same. Walking, stacked and expanding ideas may just be the start. For players, this brings a host of new innovative titles, yet it also provides developers with a framework to experiment and plot the future of iGaming.
Responsible Gambling – Gambling in all its forms is only available to those who are 18+. Gambling is a form of entertainment. You should never view it as a way to make money. If you feel gambling beyond your financial means is starting to become a problem, then get assistance. Use the limits and exclusions scheme in place at your operators, and seek third-party help.