Stacked symbols

Stacked symbols appear in vertical groups, so one symbol can fill a whole reel.

By Ryan Jessop. Last checked 9 October 2026.

Key takeaways

Stacked symbols appear in vertical groups, so one symbol can fill a whole reel.
A five-reel, ten-line slot showing one symbol on every position pays all ten lines at the top rate.
A stacked symbol arrives already tall.
Book of Dead's chosen symbol expands to fill reels in free spins, producing the same full-reel effect by a different route.

Short answer: Stacked symbols appear in vertical groups, so one symbol can fill a whole reel. When stacks of the same symbol land on neighbouring reels, they pay on many lines at once.

Why they create big spins

A five-reel, ten-line slot showing one symbol on every position pays all ten lines at the top rate. Stacks make that kind of screen possible.

Stacked, expanding and mega

A stacked symbol arrives already tall. An expanding symbol lands as one position and grows. A mega or colossal symbol is a single block several positions wide.

Among our seven

Book of Dead's chosen symbol expands to fill reels in free spins, producing the same full-reel effect by a different route.

Where to play

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Read the Casumo review Licence: Recro Limited, UKGC account 61549. Offer checked 9 October 2026.

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Read the Coral review Licence: LC International Limited, UKGC account 54743. Offer checked 9 October 2026.

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Read the Ladbrokes review Licence: LC International Limited, UKGC account 54743. Offer checked 9 October 2026.

Keep reading: Classic slots, Gates of Olympus vs Sweet Bonanza, Free demo slots.

Slot figures are developers' published defaults, each confirmed against two sources; a casino may run a lower RTP. Offer terms dated 9 October 2026. How we check. 18+. Free help: 0808 8020 133 or safer gambling.

Frequently asked questions

What are stacked symbols?

Stacked symbols appear in vertical groups, so one symbol can fill a whole reel.

What is the maximum stake on a UK online slot?

£5 a spin, or £2 for ages 18 to 24.

Where do I find a slot's rules?

In its help or information screen.

Can I try it free?

Most slots have a demo mode after age verification.

What is RTP?

The share of stakes a slot returns over a very large number of spins.

What is volatility?

How unevenly a slot pays.

Is autoplay allowed?

No, and each spin must take at least 2.5 seconds.

Can a casino change a slot's RTP?

It can choose from the versions a developer supplies.

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