Serial
Serial Stats
RTP & Maths
- RTP by Mode
- 96.07% base · 96.04% xBet
- Max Win Probability
- 1:12000000 rounds
- Max Win Rule
- 18700x main game and bonus game; up to 74800x via xBizarre gamble
Free Spins & Bonus
- Free Spins
- 3 Scatters = The Search (spins = sum of Scatter numbers) · 3 Scatters + 1 xSplit = The Kill
- Ante Bet
- 1.2x stake · xBet: +20% cost, guaranteed Scatter on reel 2
Symbols & Pays
- Wild
- xNudge reels 2-4; xSplit last reel only
- Scatter Reels
- 2, 3, 4
- Ways Pays
- Top symbol 5x · Lowest 0.1x
Serial Demo by Nolimit City
18,700x is where a round of Serial stops, before the bonus or during it. Reach that figure in the Serial demo, and the slot offers up to three 50/50 choices, each worth another 18,700x or nothing, with a wrong pick keeping what’s already been won. The 74,800x headline is that stop plus three straight coin flips. Released in November 2022, this was the Nolimit City game that introduced xBizarre. The numbers worth studying in free play are further down, on a 3-3-3-3-3 board wrapped in crime-scene tape that winning respins cut open one reel at a time.
Serial is staged in a filthy bathroom in green-grey and blood red, with a chalkboard ways count, a mirror, and pipes. A red-faced butcher in goggles leads the cast, then a special agent, a masked surgeon, a frightened woman, and a buried skeleton. Nolimit City’s Per Lindheimer said at launch that “Serial is not for the faint of heart”, and the artwork agrees with him.
Free Play Features
xWays and Infectious xWays
xWays appears by two routes only, from an opened Enhancer Cell or from a pair of Scatters changing form. It reveals a stack of 2 to 4 identical paying symbols, adding win ways, and several xWays landing together show one symbol between them. Infectious xWays arrives in the last reel’s Enhancer Cells and goes further. The symbol it reveals makes every normal-sized copy of itself on the 3-3-3-3-3 area grow to the same size.
xNudge Wild on Reels 2 to 4
The xNudge Wild is a stacked Wild for the middle three reels. It always nudges until it’s fully in view, and each nudge adds 1 to its multiplier. The less of the stack that lands in sight, the more nudges it makes and the higher that multiplier climbs.
The 2x Wild on Reel 5
The xSplit Wild lands on the last reel only and counts as a 2x Wild. It splits every symbol on its row in two, and three specials gain more than a copy. A split MISSING poster doubles the bonus spins it has, a split xNudge Wild doubles its multiplier, and a split xWays symbol doubles its size.
MISSING Poster Scatters
The Scatters are MISSING posters, and they land only on the reels between the first and the last. Each poster shows a number of spins. Two in view transform into xWays symbols, so a near-miss on the bonus reshapes the board anyway, and three start The Search.
The Search and The Kill
The Search runs for as many spins as the three posters add up to. Extra Enhancer Cells open on the inner three reels for its duration, making the reel area 3-5-5-5-3, and an xSplit Wild that lands mid-mode switches it to The Kill with 2 extra spins.
The Kill can also start directly, when an xSplit Wild lands alongside the three Scatters. It keeps every feature of The Search, and the xSplit stays on reel 5 as a jumping Wild throughout. With the doubling Wild present from start to finish, The Kill is the mode to hope for.
18,700x, Then a Choice
Once a round’s total reaches 18,700x or higher, the round stops there and xBizarre takes over. It offers up to three stages, each a 50/50 choice that adds 18,700x or adds nothing. A wrong call ends the sequence with everything already won still paid, and three right calls take the total to 74,800x, a result the game’s own simulation gives as 1 in 12,000,000 rounds. The player picks here and at no other point in a round, and the pick can’t cost anything already banked.
How to Play
Crime Tape on Every Reel
Serial dresses its board as a crime scene, with numbered evidence markers as the low symbols and police tape across every locked cell. Play opens on the 3-3-3-3-3 centre with 243 ways, and the taped Enhancer Cells above and below each reel stay shut until a win arrives. The full frame behind the tape is 5-7-7-7-5.
Ways pay for matching symbols on neighbouring reels counted from reel 1, whatever row each one lands in, and each way pays its best combination only.
A win freezes the winning symbols and awards a respin. A respin that improves the win awards another, up to 5 in a row, and each one cuts the tape off the top and bottom cells of one more reel, reel 1 first, then reel 2, and so on. An opened cell lands an xWays symbol, an xNudge Wild, a regular Wild, or a character symbol, and the ways count grows with each reel opened. With reel 1’s pair open, the chalkboard moves from 243 to 405.
The xBet switch is at the left edge of the board, under the red-and-green lights, where a thumb reaches it without leaving the reels. Flipping it guarantees a MISSING poster on reel 2 and leaves the paytable untouched.
Game RTP
Serial returns 96.07% RTP with xBet off and 96.04% with it on, so the guaranteed Scatter comes with a slightly lower return.
Nolimit City labels Serial VOLATILITY EXTREME and gives it a volatility score of 43.27, while our stats box can only show High. The studio’s figure fits a game whose low symbols pay between 0.1x and 0.9x and whose main game and bonus both stop at 18,700x before xBizarre adds three flips on top, so long quiet stretches and rare, very large rounds are the expected shape. xBet costs 1.2x the base bet for its guaranteed reel-2 Scatter; the base bet itself can be set anywhere between €0.20 and €100.
Symbol Pays
Three of a kind is the shortest win, and the butcher in goggles is well clear of the field at 5x for five, though his four pays only 0.8x. The agent and the surgeon form the next pair at 3x and 2.5x, the woman and the skeleton the pair below at 1.5x and 1x, and the five evidence markers fall in numbered order from the pliers at 0.9x to the hard hat at 0.5x.
| Symbol | 3 | 4 | 5 |
|---|---|---|---|
| Butcher in goggles | 0.5x | 0.8x | 5x |
| Special agent | 0.4x | 0.6x | 3x |
| Masked surgeon | 0.4x | 0.5x | 2.5x |
| Frightened woman | 0.3x | 0.4x | 1.5x |
| Buried skeleton | 0.3x | 0.4x | 1x |
| Evidence 1 (pliers) | 0.2x | 0.3x | 0.9x |
| Evidence 2 (chain) | 0.2x | 0.3x | 0.8x |
| Evidence 3 (gloves) | 0.1x | 0.2x | 0.7x |
| Evidence 4 (shovel) | 0.1x | 0.2x | 0.6x |
| Evidence 5 (hard hat) | 0.1x | 0.2x | 0.5x |
Ultimate Slots Verdict
Opening one taped reel per respin gives the regular game far more movement than a 5x top pay suggests, and xBizarre's flips at 18,700x put nothing already won at risk. xBet's weaker return and a theme this grim are what hold Serial back.
✓ What We Like
- Winning respins open the taped Enhancer Cells one reel at a time, adding ways and specials as the win improves
- xBizarre's 50/50 choices at 18,700x never cost what's already been won
- The xSplit Wild doubles whatever special it splits, from a poster's spins to an xNudge multiplier
✗ What Could Be Better
- xBet costs 1.2x the base bet yet returns less than standard play
- The headline top prize needs three correct 50/50 calls on top of an 18,700x round
Detailed Review
Three Flips From the Top
Serial works because of its respin board. Each win cuts the tape off another reel and drops xWays, xNudge Wilds, Wilds, or characters into the opened cells, so a 0.1x shovel line can grow into something the paytable never hints at. Once the last reel opens, Infectious xWays can resize matching symbols across the 3-3-3-3-3 centre, and that’s where the board’s upside is found.
xBizarre is the part people talk about, and it’s cleverly framed. By the time the choices appear, 18,700x is already banked and none of it is at risk, so three 50/50 calls feel like free extras. They’re also the only route to the headline figure, and a slot that turns its top prize into a coin toss is asking you to enjoy the toss as much as the prize.
Two things weigh against it. xBet charges more for its guaranteed Scatter and gives back slightly less, and the theme of chainsaws, body bags, and corpses is as grim as the studio has gone. Neither is a flaw in how the respins are built, but the first is a real cost to anyone who leaves xBet on out of habit, and the second rules it out for some players before a reel turns.
Serial followed Mental, Folsom Prison, and Tombstone R.I.P. in the studio’s run of darker releases.
For a review of a game this bleak, the surprise is how much of the entertainment comes from a chalkboard ways count ticking up.
