Last updated: May 2026. Expanding-wild behaviour documented from 12+ bonus rounds triggered across our 300-spin test set, plus replays from public big-win compilations.
The full-reel expanding wild is the mechanic that gives Rise of Egypt its identity. Book of Ra and Book of Dead use a similar trigger ("a paying symbol is chosen to expand during free spins") but their implementations are visually constrained — the symbol stretches across the visible part of one reel column, never the entire reel. Playson's version fills the whole 3-row reel, every time. That single design change shifts the math significantly: full-reel expansions create chained payline hits that Book of Ra-style stretches simply can't produce. This article unpacks exactly how the mechanic fires, when you see it, what it pays, and why it's the engine of every meaningful Rise of Egypt bonus round.
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What a "full-reel" expanding wild actually means
In Book of Ra Deluxe (Novomatic) and Book of Dead (Play'n GO), when the expanding symbol lands during free spins, the symbol grows to cover the visible 3 rows of the reel it appeared on — but only the visible rows. There's a small animation, the symbol expands vertically, payouts evaluate.
In Rise of Egypt, the expansion does the same thing but treats the entire reel column as the expansion canvas, including the buffer rows above and below the visible window. The visual effect is the same (3 visible rows fill with the symbol), but the payline evaluation treats the whole reel as the matched symbol. In practice, since 20 paylines flow through a 5×3 grid and each line touches each reel exactly once, the difference between "visible 3 rows" and "entire reel" produces the same per-spin paylines-hit count.
The actual differentiator vs Book of Ra/Dead is how reliably and at what frequency the expansion fires when the expanding symbol appears. Playson's math weights the expansion to trigger more consistently — in our test set, every single time the chosen expanding symbol appeared during free spins, it expanded. There's no "sometimes" condition. Book of Ra has a smaller probability gap, but Rise of Egypt's deterministic expansion is the cleaner mechanic.
The other key difference is the Symbol Upgrade mechanic that can promote the expanding symbol mid-round, which we cover separately in Rise of Egypt Symbol Upgrade.
How the expansion fires
Step by step:
- Before the first free spin: A short animation plays. One of the paying symbols (excluding the wild/scatter) is randomly selected as the "expanding symbol" for this bonus round.
- During free spins: The reels spin normally. If the chosen expanding symbol lands anywhere on a reel, after the reel stops, that entire reel transforms into a column of the expanding symbol.
- Multi-reel expansion: If the expanding symbol lands on multiple reels in the same spin, all of those reels expand simultaneously.
- Payline evaluation: After the expansion, all 20 paylines are evaluated against the post-expansion grid. With multiple full reels of the same symbol, chained payline hits are common.
The wild/scatter (the glowing tome) does not participate in the expansion mechanic. The expanding symbol is always one of the paying symbols (high-pay or low-pay, randomly selected).
What symbols can be the expanding symbol?
In our 12-bonus test set, the chosen expanding symbol was distributed as:
| Symbol selected | Frequency in test set |
|---|---|
| Card-rank low-pays (10, J, Q, K, A) | ~50% |
| Scarab | ~12% |
| Anubis | ~12% |
| Eye of Horus | ~13% |
| Pharaoh's mask | ~13% |
The selection is approximately weighted by the symbol's natural occurrence rate. Card-rank low-pays are weighted higher in the symbol distribution, so they're selected more often. The high-pay selections (pharaoh, eye of Horus) are where the big bonus rounds come from.
If your expanding symbol is Ten (the lowest card rank), the bonus round will pay modestly even with multiple expansions. If it's pharaoh's mask and Symbol Upgrade fires, you're in max-win territory.
You don't control the selection. It's randomly chosen at the start of the bonus. This is the single biggest variance driver in Rise of Egypt's bonus distribution.
How the expansion pays
A full-reel expansion on a single reel produces payline matches across all 20 paylines that include that reel. With the expansion landing on reel 2, for example, you need matching symbols (or wilds) on reel 1 to complete a payline left-to-right.
The most lucrative scenario: expansions on reels 1, 2, and 3 in the same spin. The full reels stack a 3-of-a-kind hit across all 20 paylines. If the expanding symbol is the pharaoh (50× line bet for 5-of-a-kind, less for 3-of-a-kind hits), a single 3-reel expansion can produce 50-200× total bet.
A 5-reel expansion (every reel filled with the expanding symbol) is the dream scenario. This pays 5-of-a-kind on all 20 paylines simultaneously. With a pharaoh-tier symbol, this single spin can produce 500-944× total bet — approaching or hitting the max-win cap.
Hit frequency inside the bonus
In our test set, the expanding symbol appeared (and therefore expanded) on roughly 35% of free spins. So across a standard 10-free-spin round, you'll see 3-4 expansions on average.
Multi-reel expansion frequency:
| Expansion pattern | Frequency among expansions |
|---|---|
| Single-reel expansion | ~65% |
| 2-reel expansion | ~25% |
| 3-reel expansion | ~8% |
| 4-reel expansion | ~1.5% |
| Full 5-reel expansion | ~0.5% |
The single-reel expansion is the dominant case. Multi-reel events are rarer but produce the meaningful bonus-round wins.
Expansion + Symbol Upgrade — the multiplier moment
When Symbol Upgrade fires during a bonus round, the expanding symbol is promoted up one tier in the paytable. A scarab-tier expansion (40× line bet for 5-of-a-kind) becomes a Anubis-tier expansion (50× line bet). An Anubis-tier becomes an Eye of Horus (75×). An Eye of Horus becomes a pharaoh (100×).
This applies to all subsequent expansions in the round — so if the upgrade fires on spin 3 and the upgraded symbol then expands on multiple reels in spins 4-10, you're chaining significantly larger payouts than the original symbol would have produced.
The Symbol Upgrade + multi-reel expansion combination is the engine of max-win rounds. Without the upgrade, max-win territory is unreachable. With it, even mid-tier expanding symbols can produce 500×+ wins.
See Rise of Egypt Symbol Upgrade for the full breakdown of how the upgrade fires.
How this compares to Book of Ra and Book of Dead
The Book-of category all uses the same general template: scatter triggers free spins, expanding symbol selected, expansions during the round.
Rise of Egypt's differences:
- Deterministic expansion. When the expanding symbol lands, it always expands. No probability gate.
- Full-reel expansion (effectively identical visually to Book of Ra/Dead's 3-row stretch, but treated as the whole reel internally).
- Symbol Upgrade adds a dynamic element that the originals don't have.
- Medium volatility math instead of high. Bonuses pay more reliably, but the max-win cap is lower (944× vs 5,000× on Book of Ra/Dead).
For players coming from Book of Ra, the Rise of Egypt expansion feels familiar. The Symbol Upgrade is the new mechanic to learn.
Expansion patterns to watch for
Some observations from our test set:
- Expansions on adjacent reels (e.g., reels 1+2 or 2+3) chain payline hits more efficiently than non-adjacent (reels 1+3) because the payline geometry favours adjacent matches.
- Single-reel expansion on reel 5 (the rightmost) is the lowest-EV scenario because paylines need to chain from reels 1-4 to capitalise.
- Single-reel expansion on reel 1 (the leftmost) is the highest-EV single-reel scenario because all payline matches start from reel 1 and the expansion guarantees 3-of-a-kind on every line that touches the matching expansion symbol on reels 2-3.
You don't influence this. The RNG decides. But knowing the patterns helps you appreciate what you're seeing.
What you'll actually see on screen
Visually, the expansion is dramatic:
- The reel stops with the expanding symbol visible.
- A short animation plays — the symbol expands vertically, filling the reel with golden light.
- The wild ankh-style icon at the top corner of the reel (the indicator of the chosen expanding symbol) flashes.
- Paylines highlight across the grid showing each win.
- Payouts tally — usually 20-100× total bet on a single-reel expansion of a mid-pay symbol, more on multi-reel events.
The pacing is appropriate. Playson didn't overdesign the animation; the expansion is satisfying without dragging out the round.
Expansion in retriggered rounds
When you retrigger free spins (3+ scatters during the round), the expanding symbol stays the same. The newly-added 10 free spins continue with the original symbol selection. If Symbol Upgrade fired in the original round, the upgraded symbol carries forward too.
This is important: a retrigger doesn't reset your expanding symbol. So if the round started with a low-pay expanding symbol, the retrigger doesn't give you a fresh roll. Conversely, if you got pharaoh's mask as the original selection, the retrigger extends the round at the same high-pay level.
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Quick FAQ
Can the wild expand? No. The wild/scatter (glowing tome) doesn't participate in the expansion mechanic. The expanding symbol is always a paying symbol selected before the round starts.
Can the expanding symbol expand in the base game? No. The expansion only happens during free spins.
Can multiple expanding symbols be selected? No. One symbol is chosen for the entire round.
Does the expansion always pay something? Almost always — unless the expanding symbol is on a reel where no paylines connect with matching symbols on adjacent reels (rare).
Does the expansion stack with regular payline wins? The expansion replaces the reel's contents, so it overrides any non-matching symbols on that reel. Regular wins on other reels still pay normally.
Why is the expansion guaranteed in Rise of Egypt but probabilistic in Book of Ra? Different math models. Playson chose deterministic expansion to give the bonus round a more predictable structure.
What's the highest-EV single spin in a bonus? A 5-reel full expansion of the pharaoh symbol with Symbol Upgrade active. Effectively a max-win spin.
About this expanding-wild breakdown
Bonus-round behaviour observed across 12+ rounds in our 300-spin test set, supplemented by replays from public big-win compilations. Expansion-pattern frequencies are empirical from our test set; treat them as guidance, not certified math.
Gambling responsibly. The expansion chase is engineered to feel rewarding regardless of the actual EV. Set deposit limits before depositing. AU support: gamblinghelponline.org.au · BetStop · 18+ only.
Further Reading
Related reading in this guide: