Starburst

Starburst keeps its format simple: five reels, three rows, ten fixed paylines, and a small set of coloured gem symbols. Paylines here pay in both directions, left to right and right to left, which roughly doubles the chances of landing a win compared with a standard one-way slot.

The starburst wild symbol expands to cover its entire reel when it lands and locks in place for a free respin, and landing wilds on adjacent reels during that respin can keep the feature going for up to three respins in a row.

NetEnt built this one at genuinely low volatility — one of the calmest on this entire page — with a payout return of 96.1%.

A reliable pick for a relaxed session with frequent small wins rather than one built around chasing a rare big feature. Twin Spin and Fire Joker share a similarly calm, classic pace.

There's no scatter symbol at all in this game; every feature runs through the expanding wild alone, which is part of why the format feels so stripped-down compared with newer releases. Starburst remains one of the most widely available slots across licensed casinos generally.

Because the entire feature set fits inside a single mechanic, new players typically understand the whole game within one or two spins. That immediate clarity is a large part of why it remains a benchmark for simple slot design.