Casino Guides: How Online Casinos Work
Online casinos work on one rule: almost every game pays back slightly less than players bet, and the share the casino keeps is the house edge. Bonuses add a second layer, with terms that decide whether you can withdraw a bonus and how much of it you keep.
These guides put a number on both, using simulations of 100,000 players, calculators you can try yourself and bonus terms we checked in our own casino accounts. VIP-Grinders has tested poker rooms since 2013 and casinos since 2024, and you will not find bonus codes or casino rankings in these guides.
Beginners can start with the two guides marked Start Here.
Casino Math: What Every Bet Costs You
The cost of playing a casino game is built into its math, and you can measure it before you bet. These guides put a number on that cost, from table games and crypto originals to slots.
Casino Bonuses: What an Offer Is Worth
The headline number on a bonus says little about what you can withdraw from it. These casino bonus guides show how the terms work and how to put a value on an offer before you claim it.
Online Casinos Explained in Four Numbers
Each guide measures one of the numbers that decide what happens to your money at an online casino:
| Number | What It Means | What We Found |
|---|---|---|
| House edge | The share of every bet the casino keeps | 0.72% on live blackjack, 14.36% on the baccarat Tie bet |
| RTP | The share paid back to players over millions of bets | The typical player got back 61% after 1,000 spins on a high volatility 96% slot |
| Wagering requirement | How much you must bet before you can withdraw a bonus | 15 in 100 players finished a $100 bonus at 40x on a low volatility slot |
| Max cashout cap | The most you can cash out from a bonus | A $100 cap cut 86% of a free spins offer’s value on a high volatility slot |
Each guide shows how its figure was worked out, so you can check it or run it with your own numbers.
How We Write These Guides
How We Test
Every guide is built on things we checked: bonus terms from our own casino accounts, RTP figures published by game providers, regulator data, and simulations and calculations we ran ourselves.
Where a figure is our own estimate rather than a published number, the guide says so.
Who Writes These Guides
Head of Publishing and Director. Sets the standards every guide must meet before it publishes.
Our Rules
We cite regulators, game providers, research studies and published casino terms, never other affiliate sites. Every figure names its source or shows how we worked it out.
If gambling stops feeling like entertainment, our responsible gambling page lists help lines and self exclusion tools by country.
Original Research and Casino Rankings
For original data on the casino market, such as monthly crypto casino deposit volumes, see our independent gambling research. When you are ready to choose a casino, see our crypto casino rankings and our comparison of every casino bonus type.