Tuning History¶
The first target was an RTP of 96% with high volatility and a good feel in play. Version 2.0.0 has a target RTP of 96.20%. Each iteration used the exact calculator first and the simulator second.
Iterations¶
| Iteration | Change | RTP | Trigger | Mean bonus | Median bonus | Result |
|---|---|---|---|---|---|---|
| 0 | First draft of the pays, the weights and the reel recipe. Bonus reel 3 has 6 KEY symbols. | 170.18% | 1 in 106.9 | 93.3 x | - | RTP much too high. The ways pays gave 62%. |
| 1 | Paytable approximately halved. Bonus reel 3 has 5 KEY symbols and one stop with two KEY symbols. | 100.92% | 1 in 106.9 | 48.4 x | 5 x | Good structure. The median bonus is low. 8.6% of the 3 FS bonuses get to level 4. |
| 2 | Weight tables become better with each level. More FISH2 symbols on the bonus reels. Fewer FS symbols. | 95.76% | 1 in 134.7 | 53.7 x | 6 x | The bonus is less frequent. The median is not much better. |
| 3 | Bonus reels have more PIC symbols and few AUS4/AUS5 symbols. Levels 2 to 4 have 8 spins (before: 10). More FS symbols. Base FISH3 weights trimmed. | 96.02% | 1 in 106.9 | 43.4 x | 8 x | Selected. More frequent bonus, better median, level 4 is rare (5.0% of the 3 FS bonuses). |
| 4 | Presentation only: shorter anticipation (1.4 s to 1.1 s for each reel), status text, reel motion that continues in a background tab. | 96.02% | 1 in 106.9 | 43.4 x | 8 x | Version 1.0.0. |
| 5 | FISH4 is the kraken. It has two values: 500 and 2000 credits, with weights 2 : 1. The mean value stays at 1000 credits. | 96.02% | 1 in 106.9 | 43.4 x | 8 x | Version 1.1.0. The RTP does not change. The standard deviation is 14.65 x bet (before: 13.02). |
| 6 | New design rules: a gap of 3 between special symbols, 3 AUS symbols in sequence at most, one KEY on each of reels 1, 2 and 3 in the base game, 2 / 2 / 1 KEY symbols on bonus reels 1 / 2 / 3. Fewer FS symbols. Golden kraken weights 8 : 1. New RTP target. | 96.2000% | 1 in 171.7 | 35.9 x | 8 x | Version 2.0.0. The standard deviation is 10.17 x bet. |
Version 2.0.0: the redesign¶
Iteration 6 changed the structure of the game. These were the steps.
- New reel rules. The gap between special symbols increased from 2 to 3. The design got a limit of 3 AUS symbols in sequence. A new generator makes strips that obey the two rules.
- KEY symbols. The base game got one KEY symbol on each of reels 1, 2 and 3 (before: one KEY on reel 3). The mean number of KEY symbols for each base spin increased from 0.04 to 0.12.
- First result. With no other change, the RTP was 105.6%. The base collect was 62.6%, and the kraken gave 48% of this. The free spins gave 8.6%.
- Free spins trigger. The target was 1 in 175. Whole FS symbols on strips of 100 symbols cannot give this value. The selected layout has FS symbols on all 5 reels (3, 2, 2, 2, 2) and gives 1 in 171.66.
- Levels. With one KEY symbol on each of bonus reels 1 to 3, levels 2, 3 and 4 came in 12%, 1.8% and 0.3% of the free spins. With 2 / 2 / 1 KEY symbols on bonus reels 1 / 2 / 3, they come in 34%, 13% and 6%. This is almost the same as in version 1.1.0. The thresholds did not change.
- Golden kraken. The weights of the two kraken values changed from 2 : 1 to 8 : 1, in the base game and in the free spins. The mean kraken value is now 666.7 credits (before: 1000). The result was an RTP of 101.9%.
- Balance. The base reel strips lost one FISH3 symbol and five FISH2 symbols, and the base weights of FISH2 and FISH3 moved to the low values. The paytable and the FISH symbols of the bonus reel strips did not change. The base weights of FISH1 are the fine adjustment: their sum is 10,000, so that the RTP is 96.199971%.
| Component | Version 1.1.0 | Version 2.0.0 |
|---|---|---|
| Base game: ways pays | 34.54% | 36.15% |
| Base game: collect | 20.90% | 39.15% |
| Free spins | 40.58% | 20.90% |
| Total RTP | 96.0177% | 96.2000% |
| Free spins trigger | 1 in 106.9 | 1 in 171.7 |
| Mean free spins win | 43.4 x bet | 35.9 x bet |
| KEY symbol in a base spin | 1 in 25.0 | 1 in 8.7 |
| KEY symbol and kraken in a base spin | 1 in 625 | 1 in 217 |
| Base spins with a win | 25.1% | 29.9% |
| Standard deviation for each round | 14.65 x bet | 10.17 x bet |
The standard deviation decreased. In version 2.0.0, a larger part of the RTP comes from the base game collect, which is frequent. A smaller part comes from the free spins.
Design decisions¶
One KEY symbol on each of base reels 1, 2 and 3. A KEY symbol lands 1 in 8.7 base spins. Two or three KEY symbols can land in one spin. Then each KEY symbol collects each FISH value.
The kraken stays on the base reel strips. The KEY anticipation on reels 4 and 5 has a purpose only if the large fish are there. The kraken gives 32% RTP in the base game. A KEY symbol and the kraken land together 1 in 217 base spins.
Golden kraken weights 8 : 1. With weights 2 : 1, the kraken gave 48% RTP in the base game, and the total was too high. The golden kraken is now less frequent. The usual kraken pays 500 credits. The golden kraken pays 2000 credits.
The balance came from the small base fish. The paytable and the free spins keep their value. The free spins are less frequent than before, so their value for each trigger must not decrease.
2 / 2 / 1 KEY symbols on bonus reels 1 / 2 / 3. This gives 0.20 KEY symbols for each free spin, the same as in version 1.1.0. The levels keep their frequency.
Eight spins for levels 2 to 4. With 10 spins, level 4 was too frequent.
Bonus reels with more PIC symbols. The bonus reel strips have no WILD symbol. More PIC symbols give more ways pays in the free spins.
Better weight tables at higher levels. The mean FISH3 value increases from 80.0 credits on level 1 to 101.0 credits on level 4.
Possible subsequent changes¶
- A variant with the kraken only in the free spins: remove FISH4 from the base reel strips and put that RTP into the free spins (mean free spins win approximately 80 x bet).
- A higher volatility variant: decrease the trigger frequency and increase the level multipliers.
- A win limit, if the market requires one.