Updated: November 16, 2020

Provably Fair Gambling – What is it? Does it really work?

“Provably fair” is one of those terms that gets a lot of attention nowadays. If you’ve ever played on an online casino there’s a good chance you have heard about it; and if you’re reading this there’s even a better chance that you would like to know more about it.

The meteoric rise of blockchain technology over the last decade has given birth to cool stuff like cryptocurrencies, smart contracts, ICO’s and many more that are still to come. This revolutionary technology is a major breath of fresh air to the gambling industry for a wide variety of reasons, with provable fairness being one of them.

What are provably fair games?

Imagine you are playing a slot or a blackjack game at an online casino. How can you know beyond any doubt that the game’s algorithm isn’t rigged to cheat you? The short answer is: you can’t. As a player you have no other choice but to trust the casino operator. This is where provably fair games can make a huge difference, i.e., players are empowered with tools that allow them to verify if a game’s outcome was truly fair, and they can do this for every round of the game if they choose to.

Giving players a sure way to test if a card shuffle was truly random or if a dice roll respected the probabilistic laws of an honest dice roll removes the previously mentioned need to blindly trust the casino. Naturally, the querying for provable fair games has seen a steady growth over the last years, as is shown in the volume of Google searches for “provably fair”:

Random Number Generation

The science of generating random numbers to ensure anti-cheating policies on casinos is called random number generation (RNG). It’s part of a scientific field that involves computational and mathematical knowledge but rest assured we won’t dive into boring technical know-how’s.

All you need to know is that RNG warrants the randomness of a dice roll, roulette number, slot symbol and so on. Companies and regulators responsible for licensing casinos evaluate the equipment’s RNG mechanism or the online casino’s server. Although blockchain ledgers may eventually change this, in most cases proving a game is fair boils down to proving that such randomness actually occurred.

How does it work?

With good technological implementation and a dash of cooperation from the operator it is possible to build games on top of a blockchain, granting transparency and immutability to the way the game operates. If you’re not sure how this is achieved with this distributed ledger technology, this two minute video explains it quite well:

If the game is not built on the blockchain then the fairness authentication may still work through manual verification. The use of open source code and/or verification tools is also added to the mix to complete the provable fairness toolkit.

How do I verify my game was really fair?

Most casinos implementing provably fair games have their own verification methods and tutorials. This is because there is a couple different ways of doing this. Here’s a very simplified version of the process, assuming the casino isn’t blockchain-based:

  • the random number used to determine the outcome of the event is calculated based on a server seed (generated by the server) and a client seed (generated by the client’s hardware)
  • players can see their own client seed because it is generated from their side; the server seed, however, is displayed as a hash (e.g.: 4b02asd9l8cocacrl119sp0x33497a) because it is encrypted
  • when the game is over the casino displays the event’s client seed; players can then input this seed into a trusted third party calculator – there are many on Google – and it will return a hash;
  • if the hash matches the server seed then you know no suspicious changes occurred within that gaming session; any mid-game changes would result in the hashes not matching.

If you just read all that blazing your eyes through it with little understanding don’t worry – it is a daunting process to go through.

Blockchain Games

In another scenario, if a casino game is blockchain-based, the verification process takes a big turn toward simplicity. Taking advantage of smart contracts in platforms like Ethereum, TRON, EOS, or NEO to build casino games means the rules will all be governed by an overseeable code. That code along with any transactions carried out on the blockchain can be publicly audited in a more robust manner. Instead of the player manually checking each round, the software can be audited once to assure no form of foul play will occur. Periodical checks can then be performed to confirm the code has not been altered. This is a big wink for players and regulators as well.

The big take here is that simply because a casino accepts Bitcoin or any other cryptocurrency it doesn’t automatically mean it uses blockchain technology in their games. They are like any other online casino out there except all transactions, deposits and payouts are done with crypto.

Although games in these casinos can still be provably fair, user experience is severely compromised if they wish to verify fairness claims. If the casino and its games are assembled with blockchain technology, they can be provably fair by design.

When should you be wary?

If you choose to play at a renowned Bitcoin casino like BitStarz you probably don’t need to worry about constantly checking if an outcome was fairly calculated. It’s highly unlikely they would risk their reputation trying to cheat players; casinos always have a long term statistical edge – meaning that, by design, they always win.

Sure, it won’t hurt you to know how to verify the fairness of a game if your full-house was just beaten by a royal flush in the final round of a poker game. That’s how those verification tools become truly useful in our opinion.

On the other hand, casinos entirely based on blockchain technology are still a relatively new thing. It’s not just about recycling the previous structure and carrying transactions with cryptocurrencies instead of fiat money. The whole thing needs to be re-designed. Players can already choose between some very good options if they want to engage in sports betting or casino games that use this technology.