How Bonus Buy works mechanically
On a slot with Bonus Buy enabled, the game shows a "Buy Bonus" button below the reels. Clicking it deducts a fixed multiplier of your bet from your balance — typically 75x, 100x, 125x, or 200x — and immediately triggers the bonus round, skipping base game spinning entirely.
The bonus round that follows is mathematically identical to the bonus round you would have triggered naturally over time. Same free spins count, same multiplier mechanics, same prize distribution. You are paying for guaranteed bonus access, not for a different bonus.
Studios price Bonus Buy at a level designed to break even on RTP. If a game’s base game spins toward the bonus at 1 in 200 spins on average, and 200x bet is the cost of a buy, then mathematically a buy costs roughly the same as 200 base spins. The buy variant’s certified RTP is usually slightly higher than the base game’s — typically 96.5% vs 96.1% — to compensate for the player’s loss of base game value.
The variance trade
Bonus Buy compresses variance in time. A natural bonus on an Extreme volatility slot might come every 200-400 base spins; spread across that many spins, the variance is absorbed by other small wins. With Bonus Buy, you experience the bonus variance every 30 seconds — repeatedly.
This matters because bonus rounds on Extreme volatility games are themselves wildly variable. The expected value of a bonus might be 80x bet, but the distribution can run from 0x to 5,000x+. Buying 10 bonuses in a row on an Extreme slot is a much wilder ride than letting them trigger naturally over an hour of base play.
Players who use Bonus Buy on Extreme volatility games typically see their session bankroll die faster than the same bankroll would on natural play. Not because the math is worse — it is identical — but because the variance is concentrated. If you bet $1 and buy 100 bonuses at 100x bet each, you are wagering $10,000 in 10 minutes, with the full extreme-tier variance applied at every roll.
When Bonus Buy makes sense
On a slot where the bonus is heavily top-loaded (the bonus contains 70%+ of the total game RTP), and where the certified buy variant RTP is meaningfully higher than the base game variant RTP, Bonus Buy can be the mathematically optimal way to play. Most modern Pragmatic Play and Push Gaming flagships fit this description.
It also makes sense when you have a fixed bankroll and a fixed time budget. If you have $500 and 30 minutes, buying bonuses gives you a much higher probability of either ending the session up significantly or busting quickly — both clearer outcomes than the slow grind of base play.
Bonus Buy makes much less sense on slots where the bonus contains less than 50% of total RTP, where the buy cost is high relative to the natural trigger cost, or where the base game itself has interesting mechanics. Some Play’n GO classics ship Bonus Buy at 100x bet but have base games that themselves produce most of the RTP — buying the bonus on those titles strips out the value you were paying for.
Multi-tier and X-iter buys
ELK Studios pioneered the multi-tier feature buy menu (X-iter), where players choose from 4-6 different buy options at different costs and different volatility profiles. A typical ELK X-iter menu has: Cost 2x bet (small enhancement), Cost 25x bet (mid bonus), Cost 100x bet (full bonus), Cost 500x bet (extreme variant of bonus), often with a Mystery Bonus option that gives a random outcome.
Each tier has its own certified RTP, with the most expensive options often at the highest RTP (97%+). Hacksaw Gaming has adopted similar tiered systems on titles like Wanted Dead or a Wild and Le Bandit. The trend is toward giving players more granular control over volatility through buy choice.
The strategic implication: the highest-cost buy is not always the best EV. Each tier is independently certified, and sometimes the mid-tier ($25-$100 bet equivalent) is the math-optimal pick. Always check the in-game info panel for each tier’s individual RTP before committing.
Jurisdictional rules
The UK Gambling Commission removed Bonus Buy from UK casinos in 2023 as a player protection measure — the regulator argued that compressing variance into rapid clicks was producing problem-gambling outcomes. Most other European regulators continue to permit it.
Several US states have followed the UK lead and prohibit Bonus Buy on regulated sites. Most European, Latin American, and Asian markets allow it. Essentially all crypto-casino operators allow it. Always verify on your specific operator before assuming — the same game can ship in two variants across two markets.
When Bonus Buy is removed for regulatory reasons, the studio typically ships a "no buy" variant of the game with adjusted base game math (slightly higher base RTP, since the bonus value is no longer guaranteed). The total RTP is usually identical to the base variant of the buy-enabled version, but the experience is different.
How to use the Bonus Buy filter on this site
Filter Bonus Buy = Yes to see every slot in the database with a buy option. Sort by Max Win descending to find buys with the highest spike potential — these are typically Hacksaw, Nolimit, and Push Gaming flagships at 10,000x to 100,000x cap.
Layer Min RTP 96.5% to find the math-friendliest buys. The result is dominated by Pragmatic and Push titles. These are the buys with the best long-run expected value, though still subject to the same variance compression issue described above.
A pragmatic rule of thumb: for a $200 session bankroll, a single Bonus Buy at 100x bet on a $1 stake costs $100 — half your bankroll on one click. If you want to use Bonus Buy responsibly, drop the bet size so a single buy is no more than 5%-10% of bankroll. On $200 bankroll, that means betting $0.20-$0.40 and buying $20-$40 bonuses. You will see less spectacular wins, but you will also have 5-10 buy attempts before bust.