Knock Knock slot: RTP and max win
Knock Knock is a high-volatility slot by Cloud STUDIO on Stake Engine, released 27 Oct 2026. The top payout is 50,000× the bet; from a base spin it lands about once every 2,369,190 spins. It has 16 bonus buys priced at 100× to 500× the bet; the best returns 96.70%, so each buy costs 3.30× the bet on average over the long run. It is the No. 439 most played Engine slot over the last 30 days.
Every mode, side by side
Costs are multiples of the base bet. Odds come from the published outcome table for v3. "Returns the cost" counts rounds that pay back at least what the mode cost. Expected cost is cost × (1 − RTP): the average amount lost per round over the long run.
| Mode | Type | Cost | RTP | Max win | Max win odds | Pays anything | Returns the cost | Expected cost per round | |
|---|---|---|---|---|---|---|---|---|---|
| Base | Base spin | 1.00× | 96.70% | 50,000× | 1 in 2,369,190 | 1 in 3.95 | 1 in 14 | 0.03× base | Simulate |
| Ante | Boosted spin | 3.00× | 96.70% | 50,000× | 1 in 635,015 | 1 in 6.90 | 1 in 31 | 0.10× base | Simulate |
| Super Ante | Boosted spin | 5.00× | 96.70% | 50,000× | 1 in 165,198 | 1 in 3.78 | 1 in 37 | 0.17× base | Simulate |
| Regular Bonus | Bonus buy | 100× | 96.70% | 50,000× | 1 in 30,000 | every round | 1 in 4.17 | 3.30× base | Simulate |
| Regular Bonus Extreme | Bonus buy | 100× | 96.70% | 50,000× | 1 in 15,000 | every round | 1 in 6.94 | 3.30× base | Simulate |
| Regular Bonus High | Bonus buy | 100× | 96.70% | 50,000× | 1 in 20,000 | every round | 1 in 5.55 | 3.30× base | Simulate |
| Regular Bonus Low | Bonus buy | 100× | 96.70% | 50,000× | 1 in 120,000 | every round | 1 in 3.21 | 3.30× base | Simulate |
| Super Bonus | Bonus buy | 200× | 96.70% | 50,000× | 1 in 5,000 | every round | 1 in 4.16 | 6.60× base | Simulate |
| Super Bonus Extreme | Bonus buy | 200× | 96.70% | 50,000× | 1 in 2,500 | every round | 1 in 6.93 | 6.60× base | Simulate |
| Super Bonus High | Bonus buy | 200× | 96.70% | 50,000× | 1 in 3,333 | every round | 1 in 5.55 | 6.60× base | Simulate |
| Super Bonus Low | Bonus buy | 200× | 96.70% | 50,000× | 1 in 20,000 | every round | 1 in 3.20 | 6.60× base | Simulate |
| Feature Spin | Bonus buy | 300× | 96.70% | 50,000× | 1 in 10,000 | – | 1 in 4.38 | 9.90× base | Simulate |
| Feature Spin Extreme | Bonus buy | 300× | 96.70% | 50,000× | 1 in 5,000 | – | 1 in 6.57 | 9.90× base | Simulate |
| Feature Spin High | Bonus buy | 300× | 96.70% | 50,000× | 1 in 6,667 | – | 1 in 5.81 | 9.90× base | Simulate |
| Feature Spin Low | Bonus buy | 300× | 96.70% | 50,000× | 1 in 40,000 | – | 1 in 3.39 | 9.90× base | Simulate |
| Mystery Bonus | Bonus buy | 500× | 96.70% | 50,000× | 1 in 1,137 | 1 in 1.82 | 1 in 6.41 | 16.50× base | Simulate |
| Mystery Bonus Extreme | Bonus buy | 500× | 96.70% | 50,000× | 1 in 1,010 | 1 in 1.82 | 1 in 7.21 | 16.50× base | Simulate |
| Mystery Bonus High | Bonus buy | 500× | 96.70% | 50,000× | 1 in 1,010 | 1 in 1.82 | 1 in 6.72 | 16.50× base | Simulate |
| Mystery Bonus Low | Bonus buy | 500× | 96.70% | 50,000× | 1 in 3,058 | 1 in 1.82 | 1 in 6.17 | 16.50× base | Simulate |
Work out the cost of Knock Knock bonus buys at your bet size
Version history
Base-mode RTP per published math version. Older versions stay public in the fairness API, so changes can be checked.
| Version | Base RTP | |
|---|---|---|
| v3 | 96.700% | Active |
Frequently asked
What is the RTP of Knock Knock?
Base spins return 96.70% of the amount wagered over the long run, from the published outcome table for version 3. All 16 of its bonus buys return 96.70%.
What is the max win in Knock Knock and how likely is it?
The top payout is 50,000× the base bet. On a base spin it lands 1 in 2,369,190 spins. In the Regular Bonus buy (100×) 50,000× lands 1 in 30,000 buys.
Does Knock Knock have a bonus buy, and what does it cost?
Yes, 16 buy modes. Regular Bonus: 100× the base bet, 96.70% RTP, an expected cost of 3.30× the base bet per buy. Regular Bonus Extreme: 100× the base bet, 96.70% RTP, an expected cost of 3.30× the base bet per buy. Regular Bonus High: 100× the base bet, 96.70% RTP, an expected cost of 3.30× the base bet per buy. Regular Bonus Low: 100× the base bet, 96.70% RTP, an expected cost of 3.30× the base bet per buy. Super Bonus: 200× the base bet, 96.70% RTP, an expected cost of 6.60× the base bet per buy. Super Bonus Extreme: 200× the base bet, 96.70% RTP, an expected cost of 6.60× the base bet per buy. Super Bonus High: 200× the base bet, 96.70% RTP, an expected cost of 6.60× the base bet per buy. Super Bonus Low: 200× the base bet, 96.70% RTP, an expected cost of 6.60× the base bet per buy. Feature Spin: 300× the base bet, 96.70% RTP, an expected cost of 9.90× the base bet per buy. Feature Spin Extreme: 300× the base bet, 96.70% RTP, an expected cost of 9.90× the base bet per buy. Feature Spin High: 300× the base bet, 96.70% RTP, an expected cost of 9.90× the base bet per buy. Feature Spin Low: 300× the base bet, 96.70% RTP, an expected cost of 9.90× the base bet per buy. Mystery Bonus: 500× the base bet, 96.70% RTP, an expected cost of 16.50× the base bet per buy. Mystery Bonus Extreme: 500× the base bet, 96.70% RTP, an expected cost of 16.50× the base bet per buy. Mystery Bonus High: 500× the base bet, 96.70% RTP, an expected cost of 16.50× the base bet per buy. Mystery Bonus Low: 500× the base bet, 96.70% RTP, an expected cost of 16.50× the base bet per buy.
Is Knock Knock high or low volatility?
High. Its base-mode standard deviation is 41.3× the bet, which puts it in the highest third of Engine games. What volatility means.
Can I check that a result was fair?
Yes. Engine games use provably fair seeds. Once your server seed is revealed you can replay any round against the published outcome table. See how to verify a result.