Freespins (free spins): how they activate and work
1. What are Frispins
Freespins is a special mode in which the player receives a predetermined number of free spins of reels while maintaining the bet, multipliers, and often with additional bonus effects.
2. Activation conditions
1. Scatter-symbols
N Scatter drop (usually 3-5) in any position.
The position is not important, only the quantity is considered.
2. Bonus-symbols
A combination of Bonus symbols on certain reels (for example, 1-3-5).
3. Buy-option
Purchase of freespins for a fixed fee - from 50 × to 150 × of the current rate.
Available in jurisdictions with a permitted Bonus Buy.
3. Mode operation mechanics
1. Number of rotations
Set by the developer: from 5 to 50 spins.
Can be fixed or variable (e.g. 10-20).
2. Payout multipliers
Applies to all winnings: × 2, × 3, × 5 and higher.
Sometimes grow with each spin according to the formula
$$
M_k = M_0 + (k - 1)imes \delta,
$$
where $ M _ 0 $ is the initial multiplier, $\delta $ is the step.
3. Sticky/Expanding Wilds
Sticky: remain on the screen for the entire mode.
Expanding: when falling out, stretch to the entire drum.
4. Retrigger
Additional free spins when N Scatter drops inside the freespins.
Often limited to a maximum (for example, + 10 spins, no more than 100 total).
4. Contributions to mathematical model and RTP
Total RTP includes payouts in both base game and freespins.
RTP of freespins may differ:
where $ W _ i $ is a win with a multiplier, $ p _ i $ is the probability of obtaining it.
Developers balance contributions so that
$$
ext{RTP}_{ext{total}} = \alpha \cdot ext{RTP}_{ext{base}} + (1-\alpha) \cdot ext{RTP}_{FS},
$$
where $\alpha $ is the fraction of rounds without freespins.
5. Example of full calculation
Slot: 10 freespins, initial multiplier × 2, retrigger chance 20%.
Average winnings in freespins without a multiplier - 5 × bets; factorized
$$
E [W] = 5imes 2 = 10\(ext {bets})
$$
Expected number of spins including retrigger
$$
N =\frac {10} {1 - 0 {,} 2} = 12 {,} 5\(ext {spins})
$$
Final contribution of Frispins to RTP
$$
\ text {RTP} _ {FS} =\frac {10imes 12 {,} 5} {1 }imes 100% = 1250 %\quad (ext {per outcome})
$$
After normalization for the mode start frequency, it is included in the general RTP.
6. Design guidelines
1. Clear activation conditions: publish the Scatter number and Buy rules in the slot description.
2. Balance of multipliers and retriggers: Too frequent retriggers and high multipliers can raise volatility to unsuitable values.
3. Limiting maximum spins: protects against an infinite cycle when retrieving.
4. Visualization and sound: separate animations and audio to keep the player's attention.
7. Conclusion
Frispins are a key tool for player retention and engagement. Competent adjustment of the number of free spins, multipliers, retriggers and the balance of their contribution to the overall RTP ensures the attractiveness of the slot and its mathematical stability.
Freespins is a special mode in which the player receives a predetermined number of free spins of reels while maintaining the bet, multipliers, and often with additional bonus effects.
2. Activation conditions
1. Scatter-symbols
N Scatter drop (usually 3-5) in any position.
The position is not important, only the quantity is considered.
2. Bonus-symbols
A combination of Bonus symbols on certain reels (for example, 1-3-5).
3. Buy-option
Purchase of freespins for a fixed fee - from 50 × to 150 × of the current rate.
Available in jurisdictions with a permitted Bonus Buy.
3. Mode operation mechanics
1. Number of rotations
Set by the developer: from 5 to 50 spins.
Can be fixed or variable (e.g. 10-20).
2. Payout multipliers
Applies to all winnings: × 2, × 3, × 5 and higher.
Sometimes grow with each spin according to the formula
$$
M_k = M_0 + (k - 1)imes \delta,
$$
where $ M _ 0 $ is the initial multiplier, $\delta $ is the step.
3. Sticky/Expanding Wilds
Sticky: remain on the screen for the entire mode.
Expanding: when falling out, stretch to the entire drum.
4. Retrigger
Additional free spins when N Scatter drops inside the freespins.
Often limited to a maximum (for example, + 10 spins, no more than 100 total).
4. Contributions to mathematical model and RTP
Total RTP includes payouts in both base game and freespins.
RTP of freespins may differ:
- $$
- ext{RTP}_{FS} = \frac{\sum (W_i imes p_i)}{ext{ставка}} imes 100%,
- $$
where $ W _ i $ is a win with a multiplier, $ p _ i $ is the probability of obtaining it.
Developers balance contributions so that
$$
ext{RTP}_{ext{total}} = \alpha \cdot ext{RTP}_{ext{base}} + (1-\alpha) \cdot ext{RTP}_{FS},
$$
where $\alpha $ is the fraction of rounds without freespins.
5. Example of full calculation
Slot: 10 freespins, initial multiplier × 2, retrigger chance 20%.
Average winnings in freespins without a multiplier - 5 × bets; factorized
$$
E [W] = 5imes 2 = 10\(ext {bets})
$$
Expected number of spins including retrigger
$$
N =\frac {10} {1 - 0 {,} 2} = 12 {,} 5\(ext {spins})
$$
Final contribution of Frispins to RTP
$$
\ text {RTP} _ {FS} =\frac {10imes 12 {,} 5} {1 }imes 100% = 1250 %\quad (ext {per outcome})
$$
After normalization for the mode start frequency, it is included in the general RTP.
6. Design guidelines
1. Clear activation conditions: publish the Scatter number and Buy rules in the slot description.
2. Balance of multipliers and retriggers: Too frequent retriggers and high multipliers can raise volatility to unsuitable values.
3. Limiting maximum spins: protects against an infinite cycle when retrieving.
4. Visualization and sound: separate animations and audio to keep the player's attention.
7. Conclusion
Frispins are a key tool for player retention and engagement. Competent adjustment of the number of free spins, multipliers, retriggers and the balance of their contribution to the overall RTP ensures the attractiveness of the slot and its mathematical stability.
