What is the difference between a bonus game that is triggered randomly and one that requires a specific symbol combination?

Two different engineering philosophies sit behind these two trigger types, and understanding them changes how you read a slot game before you spin.

Symbol-combination triggers: you can see them coming (sort of)

A bonus round can offer the chance to play a new game, often with some interaction — and it's triggered by certain symbols or combinations on the machine. The classic form is the scatter: land three (or more) of a designated symbol anywhere on the reels, regardless of payline, and the bonus game opens. Some titles require those symbols to appear on specific reels, or on consecutive reels from left to right. Others use a dedicated "bonus" symbol that must hit on every active reel simultaneously.

The defining characteristic here is visibility. The pay table explains in simple terms what needs to happen for a bonus to activate, and what exactly the bonus will be. That means you can read the rules before you play and know exactly what you're waiting for. The probability of hitting that combination is fixed by the game's math — it doesn't change based on how long you've been playing or how many spins have passed. All that controls the machine is the Random Number Generator, which freezes on a different, random combination of numbers corresponding to symbols on the screen with every spin, so each spin is independent.

Random triggers: the bonus arrives uninvited

Any other suitable game event could be utilized, such as the occurrence of a random event like selecting a random number for coin-ins and signaling the condition when the random-numbered coin-in occurs. Any condition occurring, but unrelated to the game play, can also be utilized such as a randomly set timer. In practical terms for a modern online slot, this means the RNG runs a separate, invisible draw on every spin — entirely apart from the reel outcome — and if that draw hits, the bonus fires. You might land a completely ordinary base-game result on the reels and still be launched into a bonus round.

The initiating condition for the bonus game is randomly assigned and unrelated to symbols appearing in the underlying game machine. That's the key distinction: no symbol combination is required, and nothing on the screen signals that the bonus is "close." There's no pattern to read, no near-miss to interpret. The trigger is structurally invisible to the player.

What this means in practice

From a pure probability standpoint, both types rely on the same RNG architecture — the Random Number Generator is a computer chip inside every slot machine that makes thousands of mathematical calculations per second, and as soon as you hit the button to initiate the spin, the RNG freezes on a random set of numbers that determine the corresponding symbols on the reels. The difference is whether the bonus condition is expressed as a symbol outcome or as a parallel random event.

One practical catch: because random triggers aren't tied to a visible symbol combination, some players misread them as more "generous" or more likely to hit after a dry spell. That's not how it works. Winning at slots is purely random — machines are never overdue for a jackpot, there are no tricks in how to tap the spin button, and there's no point in getting jealous if the next person to use your machine wins right after you walk away. It came down to the random number generator.

For either type, the pay table is your reference. If your machine doesn't have a label, check the pay table to see if it gives bonus rounds, and for what combinations. If the pay table describes a random trigger, it will usually say something like "may be awarded on any spin" — that's your signal that no symbol condition applies.

If you're playing on an Ontario-licensed platform, look for the iGaming Ontario and BetGuard logos on the site — those confirm you're in the regulated market. Tools like deposit limits are available through any registered operator, and if you ever want to step back, BetGuard (betguard.ca) lets anyone 19+ self-exclude from all licensed Ontario operators in a single step. Questions or concerns about gambling? ConnexOntario is at 1-866-531-2600.