How Slots Work: RTP, Volatility, Hit Rate, and RNG Explained

Slots are electronic gambling games that use computer programs to randomly select symbols on spinning reels. This guide explains how slots actually work, from the technology behind them to what affects your session results.

TL;DR

• Each spin is decided instantly by an RNG; previous spins don’t matter.
• RTP is a long‑run average (e.g., 96% over millions of spins), not a session promise.
• Volatility controls swinginess: low = frequent small wins; high = rare big wins.
• You must be 18+ to gamble in NZ. Support: Gambling Helpline 0800 654 655 — https://www.gamblinghelpline.co.nz

When you press spin, a computer randomly selects numbers that determine which symbols appear before the reels even start moving. The outcome is decided instantly by a Random Number Generator, making it impossible to predict or influence results.

Slots vs “Pokies” in New Zealand

“Slots” and “pokies” refer to the same games. “Pokies” is common in NZ; “slots” is widely understood online. The mechanics are identical: a certified RNG determines each spin. Land‑based machines and online slots use the same principles.

How Slots Work: Random Number Generators (RNG)

A Random Number Generator (RNG) is a program that creates random numbers to decide each spin.

Process:

1. The RNG continuously generates numbers every millisecond.
2. When you press spin, the current number is mapped to reel stops.
3. The reels animate to reveal the already‑decided result.
4. New numbers begin immediately for the next spin.

Key points:

• Every spin is independent — previous results don’t affect future spins.
• The outcome is decided the instant you press spin.
• No patterns: odds are the same each spin.
• Certified RNGs are audited; neither players nor venues can predict or influence outcomes.

RTP (Return to Player): What the Percentage Really Means

Return to Player (RTP) is the percentage of all money wagered that a slot pays back over a very large number of spins. The remainder is the house edge.

• 95% RTP ≈ house keeps NZ$5 per NZ$100 wagered (long run).
• 98% RTP ≈ house keeps NZ$2 per NZ$100.
• Higher RTP improves expected value over time, not a guarantee per session.

Example: On a 96% RTP slot, betting NZ$1 for 100,000 spins is NZ$100,000 wagered. The long‑run expectation is about NZ$96,000 returned and NZ$4,000 house edge. In a 200–500 spin session, results can swing widely — variance is normal.

Typical ranges seen:

Check the game’s paytable/help for RTP details and configuration.

Paylines, Ways to Win, and Bonus Features

Paylines are paths across reels where matching symbols must land to pay. Classic machines had one line; modern video slots may have 5–100+ lines with zig‑zag paths.

Ways‑to‑win systems pay when matching symbols land on adjacent reels (e.g., 243 ways), regardless of exact row positions.

• Fixed paylines: must bet all lines.
• Selectable paylines: choose how many lines.
• All‑ways pays: adjacent‑reels system.

Common bonus features:

• Free spins
• Multipliers
• Wilds and scatters
• Pick‑and‑win games
• Feature buys (where allowed)

New to bonuses and wagering limits? See Casino Bonus Wagering Explained (NZ).

Volatility and Hit Frequency: Risk and Session Feel

• Volatility (variance): how big and how swingy wins are.
• Hit frequency: how often any win occurs.

Guidelines:

• Low volatility: hit rate ~40–50%; frequent small wins — good for smaller budgets.
• Medium volatility: hit rate ~30–40%; balanced sessions.
• High volatility: hit rate ~20–30%; rare big wins — bankroll swings are larger.

Volatility impacts short‑session experience more than RTP.

Bankroll Variance: Simple Scenarios for Low vs High Volatility

Illustrative scenarios (not guarantees):

• Low volatility (NZ$0.50/spin, 400 spins)
  • Typical session band: −NZ$40 to +NZ$20
  • Many small hits; modest bonuses
• Medium volatility (NZ$1/spin, 300 spins)
  • Typical band: −NZ$150 to +NZ$150
  • Fewer hits; bonuses move the needle
• High volatility (NZ$1/spin, 200 spins)
  • Typical band: −NZ$200 most often; rare +NZ$300–NZ$1,000 spikes

For sizing stakes and session length, see Bankroll Management for Casino Players (NZ).

Denomination, Max Bet, and Jackpot Eligibility

• Denomination: the value of one credit (e.g., 10c, NZ$1).
• Max bet: the highest stake allowed per spin.
• Jackpot eligibility: some progressives require max bet for the top prize; fixed jackpots usually scale with stake.

Always check game info to see if maximum betting is required for progressive eligibility and how features scale with stake.

Common Myths vs Reality

• “Hot” or “cold” machines
  • Reality: each spin is independent; past results don’t change odds.
• Time of day matters
  • Reality: RNG runs 24/7; timing doesn’t affect outcomes.
• Button‑pressing technique changes results
  • Reality: outcome is locked the instant you press spin.
• “Machines are rigged”
  • Reality: certified RNGs are audited; the house edge exists but does not allow prediction of individual outcomes.

Responsible Gambling for New Zealand

Set limits on time and money, take breaks, and never chase losses. Venues and online sites provide tools like deposit/loss limits and self‑exclusion.

Help and support:

• Gambling Helpline — 0800 654 655 — https://www.gamblinghelpline.co.nz
• Free text support — text 8006
• Choice Not Chance — https://www.choicenotchance.org.nz

Conclusion

Slots are driven by certified RNGs; RTP is long‑run math; volatility shapes your session’s swings. Choose games that match your budget, set time and money limits, and take breaks. Need support? Gambling Helpline — 0800 654 655.