Feature Buys (or “Bonus Buys”) let you skip directly into a slot’s bonus round by paying a fixed multiple of your base bet — typically 50x to 100x. The appeal is speed: instead of grinding hundreds of base spins, you get immediate access to the high-payout feature.
The trade-off is extreme variance. Most bonus buys return well below their cost, and all the RTP is concentrated in rare large multipliers. Standard bankroll rules designed for base-game play do not apply here.
Our Bonus Buy Bankroll Simulator runs 5,000 Monte Carlo sessions across three preset volatility profiles (or a custom distribution) to estimate your Risk of Ruin (RoR) — the probability of going bust before reaching a session target. It also shows how RoR changes at different bankroll depths, so you can find the buy size your balance can actually sustain.
Bonus Buy Bankroll
RoR Simulator| Buys in Bank | Bankroll | Risk of Ruin |
|---|
How to Use the Bonus Buy Simulator
- Enter Bankroll: Your total current balance (e.g., $1,000).
- Enter Cost per Buy: The full price of one feature buy (e.g., $100). Not your base bet — the final buy-in cost.
- Select Volatility Profile:
- Low/Medium (~97% RTP): Frequent smaller returns. Fewer dead bonuses, smaller peaks.
- High (~96% RTP): Standard for most popular bonus-buy slots. Roughly half of buys return less than 25% of cost.
- Extreme (~94% RTP): Heavy dead-or-huge pattern. ~70% of buys return under 15% of cost, but the tail reaches very high multipliers.
- Custom: Enter your own 5-tier distribution if you have data on a specific slot.
The calculator displays the full payout distribution and assumed RTP for the selected profile.
- Choose Session Target: +50% profit (1.5x), Double (2x), or Triple (3x). RoR is calculated as the probability of going bust before reaching this target.
- Simulate: The tool runs 5,000 Monte Carlo sessions and shows:
- Risk of Ruin: Chance of busting before your target.
- 95th Percentile Drawdown: In 95% of simulations, your worst drawdown did not exceed this.
- Safe Bankroll (5% RoR): The bankroll level where the simulator found ≤5% bust rate.
- RoR by Bankroll Depth Table: How RoR changes at 5x, 10x, 15x, 20x, 30x, 50x, 75x, and 100x buys in bank. This is the most useful output — it shows exactly where the “safety threshold” is for this profile.
Related Tools: For general bankroll sizing, see our Bankroll Requirement Calculator. For understanding slot house edge, check the House Edge Calculator.
The Payout Distributions
The simulator uses three preset payout profiles, each calibrated so that the expected multiplier is below 1.0 (negative expectation, as with all slot games). The profiles differ in how the RTP is distributed: Low/Medium spreads returns more evenly, while Extreme concentrates almost all value in the rare tail.
High Variance Profile (~96% RTP)
| Outcome | Probability | Multiplier Range |
|---|---|---|
| Dead / Near-zero | 55% | 0x – 0.25x |
| Below cost | 25% | 0.25x – 0.75x |
| Around cost+ | 14% | 0.75x – 3.25x |
| Good hit | 4.5% | 3.25x – 7.75x |
| Big win | 1.5% | 7.75x – 52x |
In this profile, roughly 80% of bonus buys return less than the cost. The 96% RTP comes almost entirely from the ~6% of buys that return 3x or more — and especially from the ~1.5% that hit 8x+. This is why bankroll depth matters far more than RTP for short-term survival.
Extreme Profile (~94% RTP)
Dead/near-zero outcomes jump to 70%, with only ~5% of buys returning more than cost. The tail extends higher (up to 70x+), but reaching it requires surviving many losing buys in succession.
Understanding the Results
Scenario 1: $1,000 Bankroll, $100 Buys, High Variance
- Buys in bank: 10x.
- Simulation result: Risk of Ruin (before doubling) is typically in the 50-60% range.
- Interpretation: You have roughly a coin-flip chance of going bust. Ten buys is not enough cushion for this volatility — too many consecutive dead bonuses will wipe you out before a big hit arrives.
Scenario 2: Same Bankroll, Extreme Profile
- Simulation result: RoR jumps to 70-85%.
- Interpretation: With 70% of buys returning near-zero, losing 8-10 buys in a row is not unusual — it is expected. For extreme volatility, the RoR table will typically show you need 50-100x buys in bank to bring RoR below 10%.
Scenario 3: Lower Buy Size ($20 buys, $1,000 bankroll)
- Buys in bank: 50x.
- Simulation result: RoR drops to 5-15% depending on profile.
- Interpretation: This is where the bankroll starts to be deep enough to absorb the variance. The RoR table is the best way to find your personal threshold.
Model Limitations
- Generic profiles, not slot-specific. Real bonus-buy payout distributions vary by game and provider. The presets are illustrative — use Custom mode if you have actual data.
- No retrigger or cascading modelling. The simulator treats each buy as a single payout event, not a multi-stage feature with retriggers.
- Monte Carlo variance. Results vary slightly each run. The 5,000-session sample provides reasonable estimates but not exact probabilities.
- Fixed buy cost assumed. The model assumes you buy at the same cost every time. In practice, players sometimes change stakes mid-session.
- No time dimension. The simulator counts buys, not real time. A “session” ends when you bust or reach the target, regardless of how long it takes.
Frequently Asked Questions (FAQ)
What is Risk of Ruin (RoR)?
Risk of Ruin is the probability that you will lose your entire bankroll before reaching your session target (e.g., doubling your money). A 30% RoR means roughly 3 out of 10 sessions end in a bust.
How many buys do I need for a “safe” bankroll?
It depends on the volatility profile and your acceptable risk level. The RoR by Bankroll Depth table in the results shows this directly. As a rough guide: for High Variance profiles, 40-60x buys typically brings RoR below 10%. For Extreme profiles, 75-100x+ may be needed. These are model-specific estimates, not universal rules.
Why is Extreme volatility so different?
Extreme volatility slots concentrate their RTP in very rare large payouts. Most buys (often 70%+) return near-zero. This means you need a much deeper bankroll to survive the long stretches of losses between big hits. The variance, not the RTP, determines how fast your bankroll drains.
Is buying bonuses better than spinning manually?
The RTP when buying bonuses may differ slightly from base-game RTP — sometimes higher, sometimes lower, depending on the game and provider. However, bonus buying drastically increases your rate of spending (you consume bankroll much faster per minute). This makes bankroll management more critical, even if the theoretical RTP is similar.
Can I enter a distribution for a specific slot?
Yes — select “Custom Profile” from the volatility dropdown. You can set the probability for 5 tiers (Dead, Below Cost, Around Cost, Good Hit, Jackpot) and the simulator will use your custom distribution. If you have access to slot review sites that publish bonus-buy hit rates, this gives a more game-specific result.