Stacked, expanding, sticky, walking and multiplier wilds: what each one does

“Wild” is one of the most used words in slot descriptions and one of the least precise. Two games can both advertise wilds and play very differently, because the word only names the substitution job, not what the symbol does around it. The sections below go through the types one by one. Wherever possible, the wording comes from the studio's own game page (NetEnt publishes plain-language feature descriptions for most of its titles), plus one Thunderkick example from trade press. Reel layouts and rules differ between versions and between casinos, so treat every description as a pointer to the help screen, not a replacement for it.

What every wild has in common

All wilds substitute. NetEnt's page for Starburst, for example, says its wild stands in for all paying symbols. What changes from game to game is the exclusion list. In Stickers, the rules say wild symbols substitute for all symbols except Sticky Wild symbols. In Trollpot 5000, the wild substitutes for all symbols except the up arrow and Jackpot symbols. So the first thing to read in any help screen is the sentence that starts “Wild substitutes for all symbols except…”.

The table summarises the six types covered below, with one NetEnt game page for each.

Expanding wilds

The classic example is Starburst. NetEnt describes the game as a 5 x 3 slot with a maximum of 10 paylines, and its page says the Starburst symbol is an Expanding Wild: whenever it lands, it scatters clones around to cover the entire reel, and that expansion triggers a Respin. The page does not say how many respins you get or which reels can carry the wild, and review sites disagree on both points, so the in-game rules are the only reliable answer. The point of the design is simple: one symbol turns a whole column into substitutes, which makes line wins across that reel far more likely during the respin.

Sticky wilds

A sticky wild does not vanish after the spin that produced it. In Stickers, a 5-reel, 3-row game with 20 fixed paylines, a wild that appears acts as a Sticky Wild and awards one Sticky Spin. Sticky Wilds stay locked on the reels for the whole Sticky Spin session, which ends when a spin brings no new Sticky Wilds, and new ones that land during a Sticky Spin earn further Sticky Spins.

The duration is a game-level choice, which is why “sticky” alone tells you little. In NetEnt's Dead or Alive 2 the sticky wild lives in the Old Saloon and High Noon Saloon Free Spins: once a wild appears on any reel it stays in its place until the end of the Free Spins session. One game sticks for a chain of respins, the other for an entire bonus round.

Walking and shifting wilds

These two are close relatives and easy to confuse. A walking wild moves along a fixed path. In Jack and the Beanstalk, Walking Wilds can land on any reel in the main game and in Free Spins; after each re-spin they shift one reel to the left and disappear after the final re-spin on reel one. The further right a wild lands, the longer it has to walk; one that lands on reel 1 can only disappear after the next re-spin.

Thunderkick's Split Happens is described by the trade press (iNTERGAME Online) as using walking stacked wilds: bowling-pin wilds that land on reels two, three or four award at least two respins and shift one position toward the outer reels with each respin.

A shifting wild, as the word is most often used, moves because of what happened, not along a fixed path. NetEnt's Flock Me is a 6 x 7 cluster game in which the Eagle Warden multiplier wild moves to an adjacent position, up, down, left or right at random, every time it is part of a cluster win. If every neighbouring position is blocked by certain symbols, it jumps to a random eligible position instead.

Stacked wilds

A stacked wild is simply several wild positions delivered together on one reel. In Wild Bazaar the stack is a chosen Wild Spin feature: when it is activated, Wilds appear on the reels in stacks of 4. The same page lists three other Wild Spin variants, colossal 2x2 wilds, linked wilds that convert the symbols between the leftmost and rightmost wilds on a row, and a x2 multiplier wild, which shows how many different things “wild” can be inside a single game.

Stacks can also be earned. In Jack and the Beanstalk's Free Spins, keys are collected from reel 5 and the wilds change with the total: 3 keys make them Double Stacked Wilds, 6 keys make them Triple Stacked Wilds, and 9 keys turn them into the Golden Harp, an Expanding Wild that stretches to fill the reel.

Multiplier wilds, with the arithmetic

A multiplier wild changes the size of the win, not the chance of it. The cleanest rule in this set belongs to Trollpot 5000: one Multiplier Wild on a winning bet line multiplies the win by 2, two multiply it by 4, three by 8. Suppose, purely as an illustration, that a line pays R20 before the wilds are applied:

• One Multiplier Wild: R20 x 2 = R40
• Two Multiplier Wilds: R20 x 4 = R80
• Three Multiplier Wilds: R20 x 8 = R160

Other games attach different rules to the same idea. Jack and the Beanstalk says wins that include a Wild are tripled, so a R20 line win with a wild becomes R60. Wild Bazaar's x2 variant doubles all wins that include one or more wilds. In Flock Me the multiplier on the Eagle Warden rises by 1 each time it takes part in a cluster win, and in Split Happens the multiplier climbs by 1x with each respin and applies to wins that include a stacked wild. Always check whether the paytable figure you are reading already includes the wild's effect.

What the wild type does not tell you

Nothing about the type of wild states how often a game pays or how much it returns. That information is the game's RTP and hit frequency, which are printed per version in the help screen and can differ between casinos. Wild features are best read as a description of how a win is built, not as a promise of one. If you want to see where such games sit among the studio's titles, the NetEnt hub and the Thunderkick hub list the slots we have reviewed, and the best slots by studio page is the wider starting point.

A legal note for South African readers: under the National Gambling Act 7 of 2004 online casino games are not licensed in South Africa, so slots like these are offered from sites licensed elsewhere. Gambling is for adults aged 18 and over. If play stops being fun, the South African Responsible Gambling Foundation helpline is 0800 006 008, and you can SMS “HELP” to 076 675 0710.