Relax Gaming · measured RTP 107.3% · tested 2026-10-15
Book of 99
Drawn as the special symbol in round 1956, the explorer filled all five Book of 99 reels on the fourth free spin and paid FUN 10,000 alone; 30,000 demo rounds in three runs measured 107.3% RTP.
In numbers: the lab's RTP test on the official demo server measured 107.3% against 99% declared over 30,000 logged rounds in 3 runs; 30.2% of rounds paid; a natural bonus landed once per 149 rounds (202 in total) and a bonus round paid a median 50.8x the stake, mean 89.2x, trigger spin included; the biggest round paid 5,044.0x; the longest dry run was 28 spins.
Book of 99 demo
Same reels, real payouts
Cafe Casino runs the same Book of 99 with the same math and adds a welcome bonus for players from the United States:
300% up to $2,000 + 150 FS 18+ · T&Cs apply · the demo stays freeTest card
30,000 spins · FUN 2.00 bet · every request logged
| Spins | 30,000 · 3 runs |
| Bet | FUN 2.00 |
| RTP declared | 99.00% |
| RTP measured | 107.32% (approximate 95% CI 73.1–141.5) |
| Hit frequency | 30% · every 3.31 |
| Dead streak max / avg | 28 / 3.37 |
| Median hit | 0.50x |
| Max win (no bonus round) | 101.5x · run 2, round 6959 |
| Free spins, natural | 202 · 6.7 bHz · every 148.5 spins · mean bonus round payout 89.2x stake |
| Balance start → end | 5,000 → 9,390 |
- 012026-09-1910,000 rounds · 0 buysfiles & checksums ↓137.22%RTP4 files · SHA-256 ↓
- 022026-09-2110,000 rounds · 0 buysfiles & checksums ↓89.42%RTP4 files · SHA-256 ↓
- 032026-10-1510,000 rounds · 0 buysfiles & checksums ↓95.31%RTP4 files · SHA-256 ↓
each run keeps its own spin log, CSV and raw server journal with checksums; the figures on this card combine all runs
Free spins on video
natural trigger · 202 in 30,000 spins
Three Wild books open ten free spins with the meter at 26, and the natural round returns FUN 105 in total. Recorded in a separate browser session, outside the statistical samples.
Across all 3 runs the 202 natural bonuses split into 38 under 20x, 60 between 20x and 50x, 71 between 50x and 100x and 33 at 100x or more, and together they made up 56% of everything the game returned. The wait between two triggers ran from 2 to 339 spins. Payout figures here cover the whole bonus round in ordinary stakes, the trigger spin included: its scatter pays and line wins count towards the bonus.
Three Wild symbols inside the feature add 10 spins. Thirty-two of 202 rounds across three runs ran past their 10-spin start, 13 of them in run three; the 99-Wild meter opens a separate round and is not a retrigger.
- triggers 202 1 per 149 spins
- every 149 spins gaps 2 to 339
- mean 89.2x bonus round median 50.8x stake
- best 5,044.0x run 1 · round 1956
- spins per bonus 12.0 10 to 40 observed
- 01run 1 · round 195610 spins5,044.0x
- 02run 3 · round 557330 spins616.5x
- 03run 2 · round 126010 spins422.0x
- 04run 3 · round 771310 spins403.0x
Risk profile
how much bankroll the 3 runs in sequence needed
| 50 bets | bust at spin 69 |
| 100 bets | bust at spin 150 |
| 200 bets | survived all 30000 spins |
The runs are played back to back as one series, one bet size. A different session can bust earlier or never; treat this as a measured example, not a rule.
How it plays
15 rules screens from the game
Book of 99 is a five-reel, three-row book slot with 10 fixed lines that pay from the left. The explorer tops the table at 500x the stake for five on a line, the sorceress pays 200x, the ogre and the horned sorceress 75x, and the five card royals 10x to 15x; two of the top four symbols already pay. The Wild stands in for every symbol and is also the trigger: three or more anywhere start 10 free spins, and the same three Wilds award 10 more inside the feature.
The second road to the feature is the meter beside the reels. Every Wild that lands in ordinary play adds one, and at 99 the game opens a separate 10-spin round and resets the count, keeping any surplus. In the first run 3,691 Wilds arrived, 0.37 per spin, so the meter filled every 224 to 333 spins, 37 times in all, while three Wilds on one screen came 36 times with gaps from 7 to 1,069 spins.
At the start of each free-spin round one of the nine paying symbols is drawn at random as the special symbol. Whenever enough of it lands, two for a high symbol or three for a royal, it expands over its reels and pays on all 10 lines regardless of position, after the ordinary line wins of that spin. Which symbol is drawn decides the round: in the first run the explorer averaged 666x per round from its free spins over eight draws, the queen 34x over eight.
Return is set at 99.00% in the rules, with a 12,075x cap; the stake can be anything between FUN 0.10 and FUN 100 per spin. This demo carries no bonus purchase and no ante option.
Wild symbol
Scatter symbol
Free spins
Retrigger
Bet range FUN 0.10 – 100 per spin · payouts read from the game's paytable at bet FUN 2.00
Gallery
8 frames from the demo session
Verdict
The Sorceress replaced the Explorer
The drawn symbol still decides the money: in run three the Sorceress came up five times in 66 features and averaged FUN 458.60, with the two largest rounds, FUN 1,233 and FUN 806, while the Explorer, drawn once, paid FUN 101. Over 202 features in three runs the Explorer has been drawn twelve times, and eight expansions have covered all fifteen positions in 30,000 rounds, two of them in run three, both worth about FUN 300 as complete rounds.
Sample by sample the returns were 137.22%, 89.42% and 95.31%, 107.32% pooled over 30,000 FUN 2 rounds (approximate 95% CI 73.09%–141.54%, a measure of the mean's precision and nothing more) against the printed 99%; without round 1956 of run one, FUN 10,088 for the whole round, the other 29,999 rounds returned 90.51%. The base game has barely moved: paying rounds between 30.11% and 30.26% in every run, a 0.5x median hit, 20,949 blank rounds in 30,000 and no ordinary spin past 101.5x.
Free spins opened 202 times, one per 149 rounds, 110 of them from the 99-Wild meter and 92 from three Wilds, and their 56.0% share of pooled payouts comes with a 50.75x median; 32 features ran past ten spins. Wilds have landed 11,110 times in 30,000 spins, 0.37 per spin in each run, so the meter has filled 37, 36 and 37 times, a round every 273 spins on its own.
- The Sorceress drew five features in run three and they averaged FUN 458.60, the best symbol of the run
- Thirty free spins came from round 5573 of run three after two retriggers, a round worth FUN 1,233
- The meter has filled 37, 36 and 37 times in three runs, a feature every 273 spins without any Wild line
- Two full-screen expansions in run three, eight in 30,000 rounds
- No ordinary spin has passed 101.5x in 30,000 rounds
- The Explorer was drawn once in run three's 66 features, for FUN 101
- The K was drawn 13 times in run three and averaged FUN 64.85, the lowest of the nine symbols
- At its lowest, run three's balance sat 1,193 stakes under its start
Run 01·2026-09-19·137.22%
The series returned 137.22% of stake against the 99% in the rules, and one round explains the gap: round 1956 paid FUN 10,088, 5,044x, after the explorer was drawn as the special symbol and covered all fifteen positions on the fourth free spin, ten lines of five at 500x each. Without that round the other 9,999 spins returned 86.78%. The approximate 95% band, 37.6 to 236.9%, is the widest the lab has printed, which is what a single 5,000x round does to the arithmetic.
The two roads to the feature paid differently. The 37 rounds opened by the meter came like clockwork, one per 224 to 333 spins, and averaged 52x the stake as whole rounds with a 38x median; the 36 rounds opened by three Wilds averaged 202x, or 64x without round 1956, with gaps from 7 to 1,069 spins. Five rounds on each road retriggered, the longest ran 30 spins from round 590, and 13 of the 73 rounds paid under 20x.
Ordinary play is a delivery service. Something paid on 29.6% of ordinary spins, mostly at 0.5x, no ordinary spin passed 101x, and the balance sat 178 stakes below the start before spin 1956 lifted it 5,043 stakes in one round. Expansions are the money: 736 of the 860 free spins expanded at least one reel and those pays were 59.8% of everything the series returned. Three expansions covered the whole screen, and the two that drew a royal, the 10 on round 7201 and the jack on round 9497, paid FUN 200 apiece against FUN 10,000 for the explorer.
Run 02·2026-09-21·89.42%
The second series returned 89.42% of stake against the 99% in the rules, an approximate 95% band of 73.7 to 105.1% that still holds it, and closed 1,058 stakes down after a 1,820-stake drawdown that bottomed at spin 8438. Fifty stakes lasted 62 spins, a hundred 155 and two hundred 438, where the first run's two hundred survived the session. Something paid on 30.26% of spins at a 0.5x median, four droughts passed 20 spins and the longest ran 24, and no ordinary spin beat 101.5x, on round 6959.
The draw decides the round, and this time it never drew the top symbol into a good round. Sixty-three features arrived, one per 159 spins, and paid 65.97x the stake on average for the whole round with a 54.0x median, 46.5% of everything returned; the explorer came up three times and averaged 31x from its free spins, against eight draws and 666x in the first run. Round 1260 led the session at 422x on a jack, round 1430 covered the whole screen twice with queens across 30 spins for 305x, and round 8831 did it once with kings for 281.5x; the weakest round paid 5.5x, and thirteen stayed under 20x.
The two roads into the feature stayed close to their first-run rates. Three Wilds opened 27 rounds, the 99-Wild meter 36, and the meter's rounds again paid less, 45.65x the stake on average as whole rounds against 93.06x for the Wild-triggered ones. Wilds landed 3,732 times in 10,000 spins, 0.37 per spin, and 645 of the 730 free spins expanded at least one reel, 88.4% of them.
Run 03·2026-10-15·95.31%
The Sorceress was drawn five times out of 66 and those five features averaged FUN 458.60, the highest of any symbol in the run: round 5573 opened from the 99-Wild meter, retriggered twice to 30 spins and paid FUN 1,233, FUN 800 of it on spin 23, and round 7713 took FUN 802 on its sixth spin after three Wilds opened it. The Explorer came up once, for FUN 101. Two expansions filled all fifteen positions, the J on spin twelve of a 20-spin feature and the Q on spin four of another, worth FUN 294 and FUN 306 as complete rounds.
The meter opened 37 features and three Wilds 29, one feature per 152 rounds in all; the Wild road averaged FUN 171.66 against FUN 116.62 for the meter, and 13 features ran past ten spins, nine to twenty, three to thirty and one to forty. Bonus rounds supplied FUN 9,293 of the FUN 19,061 returned, 48.8%, and the 10,000 FUN 2 rounds closed at 95.31%, with 6,989 blank rounds, a 28-round dry stretch from 4355 to 4382 and the balance 1,193 stakes under its start at the lowest point. Wilds landed 3,687 times, 0.37 per spin, and no ordinary spin passed 101x.
Test record
3 runs · 30,000 rounds · 0 buys · open data · closed rig
This game has been through 3 separate test runs on the official demo server, each a fresh session of 10,000 rounds at a fixed bet. Every figure on this page combines the runs into one sample, as if they were one long session; the record below keeps each run apart, with its own numbers and its own downloadable log.
- 30,000rounds, all runs
- 30%rounds that paid
- 5,044xbiggest round
- 1 / 149natural bonus rate
- 28longest dry streak
01run Run 012026-09-19 measured return137.22%+38.2 pts vs declared
- 95% band
- 37.6–236.9%
- rounds that paid
- 30%
- biggest round
- 5,044x · round 1,956
- longest dry streak
- 18
- natural bonuses
- 73 · one per 137 rounds
- balance start → end
- 5,000 → 12,444
- deepest drawdown
- 1,488x
02run Run 022026-09-21 lab note measured return89.42%-9.6 pts vs declared
- 95% band
- 73.7–105.1%
- rounds that paid
- 30%
- biggest round
- 422x · round 1,260
- longest dry streak
- 24
- natural bonuses
- 63 · one per 159 rounds
- balance start → end
- 5,000 → 2,885
- deepest drawdown
- 1,820x
Second run, two days after the first: the return fell from 137.22% to 89.42%, and the pooled 62.9 to 163.8% band still holds the printed 99%. The difference is the draw: the explorer was picked three times here against eight in the first run, so the best round paid 422x instead of 5,044x, and bonus rounds made 46.5% of the return against 67.1%. Features came 63 times against 73, and the meter again delivered a round every 278 spins on its own.
03run Run 032026-10-15 lab note measured return95.31%-3.7 pts vs declared
- 95% band
- 76.1–114.5%
- rounds that paid
- 30%
- biggest round
- 617x · round 5,573
- longest dry streak
- 28
- natural bonuses
- 66 · one per 152 rounds
- balance start → end
- 5,000 → 4,061
- deepest drawdown
- 1,193x
Run three came in at 95.31%, between run one's 137.22% and run two's 89.42%, with 66 features, the same 0.37 Wilds per spin and two full-screen expansions against six in the first two runs together. The Explorer was drawn only once; the Sorceress, drawn five times, produced the two largest rounds, FUN 1,233 and FUN 806.
3 test runs combined into one sample (2026-09-19, 2026-09-21, 2026-10-15): 30,000 ordinary rounds, including naturally triggered features, at a fixed FUN 2 bet; recorded on the official Relax Gaming demo server (jurisdiction MT, RTP profile 99.0%); every request and response logged.
The test rig plays the official demo build over the network and records every server round: bet, win, intermediate steps (cascades, respins), free spins, collect. Screenshots and video were captured in a separate browser session and are not part of the statistical samples. The text was read against the log by an editor before publication. How we test →
FAQ
5 questions · answered from the log
Is Book of 99 above its 99% setting after three runs?
Yes, and by eight points: 107.32% over 30,000 FUN 2 rounds, from 137.22%, 89.42% and 95.31% by run; the latest paid FUN 19,061 on FUN 20,000, and two of the three samples finished under the printed figure.
Which symbol did run three's features draw most often?
The Q and the K, 13 times each, then the J and the A nine times each, the Ogre and the horned sorceress six each, the Sorceress five, the 10 four and the Explorer once. Money went the other way: the Sorceress's five features averaged FUN 458.60, the K's 13 averaged FUN 64.85.
Did any expansion fill the whole screen in run three?
Yes, twice: the J on spin twelve of a 20-spin feature and the Q on spin four of a 10-spin one, for complete rounds of FUN 294 and FUN 306. The series now has eight full screens in 30,000 rounds, the Explorer's in round 1956 of run one still the only one worth FUN 10,000.
Which road into the feature paid more in run three?
Three Wilds: their 29 features averaged FUN 171.66 against FUN 116.62 for the 37 opened by the 99-Wild meter, and yet the meter road's best, round 5573, was also the run's best at FUN 1,233 for the whole round. Across three runs the meter has opened 110 features and three Wilds 92.
How many features ran past ten spins in run three?
Thirteen of 66: nine reached 20 spins, three reached 30 and one 40, all from three Wilds landing inside the feature. Run one had ten such rounds and run two nine, 32 in all.
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- spins30,000
- bet2.00
- result+2,195x
- RTP measured107.3%
- bonuses202
- max win, no bonus101.5x














