Progress Bars and Persistent Features Persistent Features (Progress Bar)
Features like gauges, levels, and collection records that don't disappear when a spin ends but carry over to the next one. Fill them to the required amount and rewards such as free spins, higher multipliers, and extra spins open up.
| English | Persistent Features (Progress Bar) |
|---|---|
| Classification | Game Features |
| English | Persistent Features / Progress Bar |
| Also called | Gauge, meter, progress bar, level system |
| Category | Bonus feature |
| Main forms | Base game gauge / Progress bar inside the bonus / Floor climbing |
| Featured games | Vikings Go Berzerk, Steam Tower, Big Bass Bonanza |
| RTP | Average of all states |
Overview
Progress bars and persistent features (Persistent Features, Progress Bar) is the general term for mechanics where a slot remembers the result of a previous spin and carries it into the next one. In a typical slot, the screen returns to its starting state once a spin ends. In a game with persistent features, a gauge that has filled up a bit or a level that has gone up stays as it is.
Players can see “how much they’ve collected” with their own eyes, which gives them a goal, and providers can tie short spins together like a longer story. That’s why progress bars have become a popular presentation device both inside and outside free spins.
What it remembers
| Category | Where it builds up | When it’s full |
|---|---|---|
| Base game gauge | Each time a certain symbol or win appears on a regular spin | Bonus entry, special mode triggered |
| Progress bar inside the bonus | Each time a certain symbol is collected during free spins | Extra spins, higher multiplier (linked to retriggers) |
| Climbing floors and levels | One step up each time a wild or similar symbol appears during the bonus | The higher the floor, the larger the multiplier and prize |
Examples in games
Vikings Go Berzerk (Yggdrasil, November 2016) gives each Viking character its own rage gauge. Every win that includes that Viking fills the gauge, and once it’s full, that Viking enters Berzerk mode and gets 7 free spins. A Viking in Berzerk mode isn’t blocked by the obstacle characters and turns into a sticky wild.
In Steam Tower (NetEnt), when hero symbols fill an entire reel, the tower climb begins along with 10 free spins. Each wild moves you up one floor and adds 2 spins. Floors 1-3 carry a 2x multiplier, the top floor (16) carries 7x, and a separate bonus prize is awarded.
In the free spins of Big Bass Bonanza, the number of fisherman wilds collected builds up at the bottom of the screen. Every 4 you collect adds 10 more spins, and the multiplier rises to 2x, 3x, then 10x. Wheel O` Gold also fills a gauge with 4 bonus symbols during free spins, and then a wheel spins to add a multiplier.
| Games | Highlights | RTP | Max win |
|---|---|---|---|
| Vikings Go Berzerk | Rage gauge for each Viking | 96.1% | 4,000x |
| Steam Tower | 16-floor tower climb, max 7x | 97.04% | 1,000x |
| Big Bass Bonanza | Fisherman collection stages (2x, 3x, 10x) | 96.71% | 2,100x |
| Wheel O` Gold | Gauge with 4 bonus symbols | 96.02% | 10,000x |
What to keep in mind about the odds
In games with persistent features, the value of the next spin can change depending on the state of the screen. For example, if a gauge is almost full, the distance to the reward is short. Conversely, from a fresh start you have that much more to build up. The RTP a game publishes is an average of all these state changes from start to finish.
So a well-filled gauge doesn’t mean the game is “about to hit.” Being closer to a reward and being guaranteed a big win are different things. What fills the gauge, and whether it’s kept if you leave and return to the game, varies by game, so check the rules screen (hot and cold slot myths).
