Expanding wild slots

What expanding wild slots are

An expanding wild is a wild that lands on one position and then grows to fill every position on its reel. For that spin, the whole reel substitutes for the regular symbols. Expanding wild slots are games built around this behaviour, often adding a respin, a multiplier or an upgrade when the wild expands.

It is one of the oldest modern slot features and still one of the easiest to follow: a wild lands, a column lights up, and you can see straight away which lines it helps. The value comes from geometry, which the next two sections work through.

Why a full wild reel matters on paylines

On a payline game, every line passes through exactly one position on each reel. A reel that is wild top to bottom is therefore part of every line at once. One wild on a single position might sit on three or four of ten lines; the same wild expanded sits on all ten.

Blueprint’s Eye of Horus shows how far this goes. Its Horus wild lands only on reels 2, 3 and 4 and expands to fill the reel. Suppose all three expand on one spin:

1. Reels 2, 3 and 4 are entirely wild, so every one of the 10 lines has three wilds in a row after reel 1.
2. Whatever symbol each line crosses on reel 1 now has at least four of a kind on that line.
3. If reel 5 also shows a matching symbol on some lines, those lines pay five of a kind.
4. All 10 lines pay on the same spin, so the total is the sum of ten line wins rather than one.

Because reel 1 never holds a wild, every win still needs a real symbol there, which keeps the base game from paying too freely. In free spins, each Horus wild also upgrades the lowest picture symbol, so later spins carry more valuable symbols.

Expanding wilds on ways-to-win games

On a 243 ways game, wins count every combination of matching symbols on adjacent reels from the left. An expanded wild multiplies those combinations. Take a 5×3 grid where your symbol appears once on reel 1 and once on reel 2. With a single wild on reel 3, there is 1 × 1 × 1 = 1 way through it. With reel 3 fully wild, there are 1 × 1 × 3 = 3 ways, so that three-of-a-kind pays three times. If reel 2 held your symbol twice, it would be 1 × 2 × 3 = 6 ways.

The effect is the same idea as on lines, counted differently: a full reel lets every matching symbol on the earlier reels connect through all three rows.

Expanding wilds vs the expanding symbols in book slots

Book slots such as Book of Dead have a feature that looks similar but works differently. Before free spins, one regular symbol is chosen at random. When enough of it lands, it expands to fill its reels and pays across every line, usually even on reels that aren’t next to each other.

• An expanding wild substitutes for other symbols, so it helps complete their wins.
• An expanding symbol doesn’t substitute; it pays as itself, for its own line value.
• Expanding wilds usually appear in the base game and the bonus; book-style expanding symbols appear only in free spins.

Our book slots page covers the expanding symbol family in depth.

Six ways games build on the expanding wild

Expanding wild slots compared

Reviews: Starburst XXXtreme, Eye of Horus Megaways, Divine Fortune and Hall of Gods.

Starburst’s expand-and-respin, worked in pounds

Starburst is the purest expanding wild game. Wilds land only on reels 2, 3 and 4. When one lands, it expands, holds in place and triggers a respin; any new wild on the respin also expands and holds, up to three respins. Wins pay both ways on its 10 lines, so a full wild reel can complete wins from the left and from the right.

Here is an illustration at £1 a spin (10p a line). A wild expands on reel 3, and the spin pays two small line wins worth 20p each: 40p. On the respin, a second wild expands on reel 2 and holds; with two wild reels in the middle, four lines now pay 30p each: £1.20. A third wild could leave reels 2, 3 and 4 all wild together, the usual route to Starburst’s biggest results; its cap is 500x, or £500 at £1. The line values are invented; the sequence is the game’s own. Most expansions end after one respin with a modest win, which is why the game is low volatility.

Expanding wilds with multipliers and the big caps

A plain expanding wild can only do so much; it covers a reel. Attach a multiplier and the ceiling rises sharply. Starburst XXXtreme keeps the original’s expanding wilds but adds random multiplier wilds from x2 to x150, which is how a game with the same look reaches a 200,000x cap at high volatility. Zeus vs Hades uses expanding wilds with multipliers up to 100x. In Wanted Dead or a Wild, VS symbols expand into multiplier wild reels, and when several sit on one line their multipliers add together.

An illustration on Wanted Dead or a Wild: a line win worth 20p crosses two VS wild reels showing x10 and x25. Added together that is x35, so the line pays £7. These big multipliers are rare, and they are the reason such games swing far harder than Starburst. Our guide to how multipliers work compares added and multiplied multipliers.

Volatility patterns and UK rules

Expanding wilds on their own tend to produce steady, moderate wins, which is why Starburst and Hall of Gods sit at the low end. Volatility climbs as games attach multipliers, upgrades or bonus-only wild reels. In our table, five of the eight are high or above. On 200 spins at 50p, £100 staked, Starburst’s 96.09% implies a theoretical cost of £3.91 with frequent small returns; Eye of Horus Megaways at 95.49% implies £4.51, delivered far less evenly. UK rules apply to all of them: £5 a spin from age 25, £2 for 18 to 24-year-olds, at least 2.5 seconds per spin, no autoplay or turbo, and no bonus buys.

How to read an expanding wild slot

1. Check which reels the wild can land on; middle-reel wilds behave very differently from wilds on every reel.
2. Read what happens after it expands: respin, upgrade, multiplier or nothing extra.
3. Find out whether lines pay one way or both ways, as both-ways games get more from a full wild reel.
4. Confirm the RTP in the help screen; Eye of Horus and its Megaways version come in several versions.
5. Multiply the max win by your stake so you know the real ceiling.
6. Set a session budget and stake before you start, and stick to them.

Where to play expanding wild slots

Search a UK-licensed casino’s lobby for the game and check its RTP before depositing. New UK customers (18+) at 10bet who pick the casino welcome bonus and deposit within 7 days get their first deposit matched 100% up to £25; wager the bonus 10x on slots within 3 days, and note that bonus winnings are capped at £1,000. Coral gives new players (18+) 100 free spins at 10p each on selected games after depositing and betting £10 on slots, with no wagering on winnings; accept within 48 hours and use within 7 days, and some payment types don’t qualify. Terms apply.

18+. Gambling should be entertainment that costs money, not a way to make it. Set a deposit limit before you play: how to set limits. Free, confidential help: National Gambling Helpline 0808 8020 133.