04 — features
Buy bonus
There is no special "bonus buy" primitive on the platform — and you don't need one. Every Stake-style purchase is just a bet with a bigger stake. The bank neither knows nor cares that it was a bonus buy; it locks a stake and pays a win.
How each feature maps
| Feature | How you model it |
|---|---|
| Normal spin | /bet/open with amount = bet |
| Buy bonus / buy free spins | /bet/open with amount = bonus price(e.g. 100× bet), run the free-spins math in your game, settle the total win in one /bet/settle |
| Buy multiplier / buy feature | same — amount is the feature's price; your paytable for that mode sets the payout distribution |
| Retriggers, sticky wilds, … | purely game-side: keep drawing from /random and accumulate, settle once at the end |
A bonus buy is still one round
open(bet_id, amount = 100 × bet) // lock the bonus price → /random, /random, /random, … // as many draws as the feature needs → your free-spins math accumulates the total win settle(bet_id, payout = total win) // one settle for the whole feature
Any number of draws can live between one open and one settle. The nonce keeps advancing per draw, so the entire feature stays deterministic and verifiable from the seed.
Several different bonuses?
Sell as many as you like — bonus hunt at 2×, free spins at 100×, super bonusat 500×. Each is just a different price on the open, with its own tuned math in your game.
Tune the RTP per mode
Design the RTP of each buy-mode in your paytable separately from the base game — exactly the way Stake tunes buy-bonus RTP on its slots. Tell us the target RTP of every mode when you deliver: we monitor realized RTP per game in production.