89PHP Expanding Wild: How It Differs From Sticky and Stacked Wilds

An expanding wild is a wild symbol that grows after it lands, most often until it covers every position on its reel. The word “wild” alone tells you very little, because studios use it for several different behaviours. Read the type before you spin, and you know what a wild can and cannot do in that game. Start with the wider picture in how online slot machines differ.

What an expanding wild does

A wild substitutes for regular symbols to complete a winning combination, as set out in the wild symbol meaning. The expanding version adds one step: after landing, it spreads over its reel. A single symbol on a 3-row reel then covers 3 positions, and on a 5-row reel it covers 5.

1. The wild lands on a reel as one symbol.
2. The reel fills with wilds, in the direction the game’s rules state.
3. The game then checks for wins with every position on that reel acting as a wild.

Expanding wilds usually do not replace scatter symbols. Check the paytable for the exact list, since the same word can mean different things in different games.

Expanding wild against sticky, stacked and walking wilds

The easiest test is to ask what happens after the symbol lands.

1. If it grows, it is expanding.
2. If it stays, it is sticky.
3. If it arrived tall, it is stacked.
4. If it moves, it is walking.

A worked example on a 5-row reel

Say a reel shows 5 positions and an expanding wild lands on the second one. After expansion all 5 positions are wild. Any matching symbols on neighbouring reels can then connect through that column.

With a ₱20 stake and a line win of ₱60 on that spin, the wild did not change the stake or the maths of the next spin. It only changed the result of the spin it appeared on. This is an example with round numbers, not a typical result.

Wild behaviour in the 16 titles on this site

None of the 16 titles in this site’s data lists an expanding wild in its feature text. They use other wild behaviours, which makes them useful contrasts:

1. Big Bass Bonanza and Big Bass Splash: a fisherman wild that collects the values of money fish symbols during free spins.
2. Mahjong Ways and Mahjong Ways 2: wild symbol transformation, with golden tiles converting to wilds.
3. Wild Bandito: gold-framed symbols that act as wilds.
4. Treasures of Aztec: mystery symbols that upgrade to wild.

For any other title, open the game’s info screen and read the wild entry. The feature text on this site names the mechanic only where the studio’s data does.

Does an expanding wild change the odds?

An expanding wild is part of the game’s built-in maths, and the studio sets that maths. Its effect appears in the published RTP, if the studio publishes one, and it cannot be switched on, switched off or timed. See the highest RTP slots ranked by figure for the titles that print a figure.

Three checks before you play a title with any wild:

1. Read the wild type on the info screen.
2. Read the maximum win, since a wild alone does not set the size of a big result. The size of a mega win depends on the stake and the game’s rules, as explained in what a mega win slot banner means.
3. Pick your stake and your stop point first.