Crypto casinos verify game fairness in layers. Slot and live-dealer studios have their random number generators and game maths certified by independent test labs such as GLI, iTech Labs, eCOGRA or BMM. The licence adds rules and supervision on top. In-house games are usually provably fair, so you can check each result yourself. A few blockchain games prove their randomness on-chain.
Who controls the randomness in each game
The question "is this casino fair?" splits into several smaller ones, because a typical crypto casino lobby mixes games from different sources. The casino itself often does not generate the random numbers for most of what you play. Which layer protects you depends on the game you open.
| Game type | Who generates the outcome | How it is checked | What you can check yourself |
|---|---|---|---|
| Third-party slots and RNG table games | The game studio's server | Lab certification before release, licence conditions, RTP monitoring | The RTP and rules in the game's info panel |
| Live dealer games | Physical cards, wheels and dice in a studio | Studio procedures, equipment checks and audits | The video stream and the published rules |
| Casino originals (crash, dice, plinko, mines) | The casino's own server | Provably fair commitment; sometimes lab testing too | Every individual result, from the seeds |
| On-chain games | A smart contract using verifiable randomness | A cryptographic proof checked on the blockchain | The proof and the transaction |
For most players the first row matters most. Pragmatic Play appears among the named studios of 26 of the 29 trading casinos in RollShark's records, Hacksaw Gaming in 23 and Evolution in 21, as of October 2026. When you spin one of their slots at a crypto casino, the result comes from the studio's own systems, not the casino's.
Certified RNGs and what "random" has to mean
A random number generator in a casino game is software that produces a stream of numbers no one can predict. Regulators spell out what that has to look like. The UK Gambling Commission's technical standard RTS 7 is one of the most detailed public examples. It requires that RNG output be "acceptably random", which it breaks down into specific qualities:
- Numbers are spread evenly across the whole range, and game outcomes follow their stated probabilities.
- The next number cannot be predicted without knowing the algorithm and the seed.
- The generator does not repeat its own sequence or fall into step with another instance.
- Seeding and re-seeding do not make results predictable.
- Any scaling of raw numbers into game results keeps those qualities.
The same standard bans "compensated" games that adjust their odds during play, requires random numbers to be used in the order they arrive, and prohibits swapping one losing result for a more tempting near miss. Those rules target a step where bias can creep in unnoticed: the mapping from a raw number to a reel stop or a card.
Crypto casinos are rarely licensed in Britain, but many of the studios supplying them also sell into regulated markets and have their games tested to those standards. Offshore licences carry their own version of the rule. Anjouan's regulator states that RNGs used in gaming products must be certified by an approved independent testing facility and that game rules, odds and payout information must be disclosed.
Independent test labs and what a certificate covers
The labs that do this work include Gaming Laboratories International (GLI), iTech Labs, eCOGRA and BMM Testlabs. GLI also publishes technical standards that many regulators use as a starting point, including GLI-19 for interactive gaming systems. A studio sends a game to a lab before release, and the lab typically examines four things:
- The RNG, through statistical testing of very large samples of output and a review of how it is seeded.
- The game maths, confirming that the paytable and reel strips produce the theoretical RTP the studio claims.
- The source code and the mapping from random numbers to outcomes, looking for errors or hidden behaviour.
- The build itself, so that the version certified is identified and later changes can be spotted.
A certificate is narrower than its logo suggests. It covers a named game version, often for named jurisdictions, as tested on a given date. It says nothing about how the casino handles your account, bonuses or withdrawals, and an operator showing a lab badge in its footer has not necessarily had anything of its own tested. Where a casino's own platform or RNG has been certified, the operator usually says so specifically, and that claim is worth tracing. In our records, Wild.io's Originals page says every Wild Originals game is tested and certified by iTech Labs, and Wolfbet's home page cites iTech Labs certification for its RNG, although we found no certificate or report linked on Wolfbet's site.
Regulated markets also require ongoing checks after launch. Under the UK Gambling Commission's testing strategy, the RNG and the scaling and mapping of results must be assessed by an independent third party, live dealer operations need independent assurance, and security is audited annually.
RTP: who sets it and who watches it
Return to player is the share of all money wagered that a game is designed to pay back over a very long run. The studio sets it when it designs the maths, the lab confirms it, and the casino chooses which games to offer. A crypto casino cannot quietly change a certified third-party slot's maths without the studio's involvement.
Watching RTP in live play is a separate job. The UK Commission expects operators to compare actual RTP against the advertised figure on a schedule tied to volume of play, and notes that where a studio supplies games to many casinos, the studio is likely to run that monitoring because it holds the combined data. Measured RTP is simply total winnings divided by total stakes.
Some crypto casinos publish more than the minimum. Thunderpick shows each game's RTP behind an information icon in the lobby, according to one third-party review. Roobet shows live paid-out RTP for slots over the last ten minutes, hour and day, according to provably.com. Cloudbet's fairness page says actual RTPs are compared with theoretical ones every quarter, though it names no testing lab. If you mainly play slots, the guide to crypto casinos for slots goes further into choosing titles by RTP.
What the licence adds
A licence turns fairness from a promise into a condition that can be enforced. The regulator can demand records, suspend the operator or revoke the licence if games are not run as described. How much that protects you depends on the regulator.
Curaçao's Gaming Authority has licensed online gaming directly since the National Ordinance on Games of Chance took effect on 24 December 2024. Anjouan's authority publishes regulatory standards, a public register you can search by licence number or domain, and a complaints route: game outcome disputes must reach the operator within 14 days of the session, and unresolved cases go to an approved dispute resolution provider rather than to the regulator.
A licence number is the starting point for any check. Of the 29 trading casinos with a full RollShark record, 24 have a licence number on record. Where records are messy, we say so in the review. The table shows the range, as of October 2026.
| Casino | Licence detail in our records | Fairness disclosure |
|---|---|---|
| Wild.io | Anjouan, number published and valid on the regulator's register; a Curaçao certificate also lists the domain | 15 Wild Originals with a seed checker |
| Wolfbet | Anjouan, number published, valid to May 2027 on the register | Per-game HMAC-SHA256 method published; iTech Labs cited, no certificate linked |
| Cloudbet | Curaçao, number published, shown as Active | 15 Originals on SHA3-256 and SHAKE256; Dice and Plinko at 99% RTP |
| Instant Casino | Curaçao number published and listing the domain, held by Axenora Strategic Services N.V.; Casino Guru still lists it as unlicensed | No originals; marketing calls results "verifiable", the terms promise only lab-tested third-party games |
| TG Casino | Tobique page marks tg.casino as pending; a Curaçao licence tied to it by FinTelegram is revoked | TGC originals reported by a third party; no seed documentation found |
| Vave | No licence found for vave.com; Dutch regulator fined the operator €3.08 million in June 2026 | No operator page names provably fair originals; a "flat 99% RTP" claim is unconfirmed |
One timing caveat: in early October 2026 the Curaçao Gaming Authority's online portal was still offline after unauthorised access it disclosed in September. Its notice says existing licences remain valid, and individual licence certificates still load, so a Curaçao number can often be checked through the certificate link on the casino's own site.
Live dealer games
A live roulette spin or blackjack deal has no software RNG to certify. Fairness rests on the equipment and the people: balanced wheels, properly shuffled shoes, camera coverage, dealer procedures and audits of all of it. In the UK, operators running live dealer games must get independent assurance from a regulator or test house that the operation meets the standard.
At crypto casinos these tables almost always come from a handful of studios, mainly Evolution, Pragmatic Play Live, Ezugi and Playtech in our records. That helps the player, since those studios also supply regulated markets and are supervised there. What you cannot do is check an individual round, as you can with provably fair games. Compare lobbies on the live crypto casinos page.
Provably fair, in brief
Casino originals add a layer that regulated slots lack: the casino publishes a hash of a secret server seed before you bet, combines it with your own client seed and a bet counter, and reveals the seed afterwards so you can recompute the result. It proves the outcome was not changed after you bet. It does not prove the payout table is generous or that the formula turning hashes into results is unbiased.
The mechanics, with a worked example you can check by hand, are in how provably fair games work.
On-chain randomness and VRF
A smaller group of blockchain-based games moves the random number itself on-chain. A common tool is a verifiable random function, or VRF. Chainlink's version, for example, generates a random value together with a cryptographic proof that is published and verified on-chain before the game contract can use it. The player does not have to run any check, because the contract rejects a value whose proof fails.
VRF has limits. Chainlink's own documentation notes that an attacker who stole the randomness key and could also build blocks on the target chain could bias results. Each request also costs a fee and waits for a blockchain transaction, which suits slow lottery-style draws better than fast games. None of the brand records RollShark holds describes VRF-based casino games, so for now it is mostly a feature of decentralised gambling apps, not of the custodial crypto casinos most people use.
How to check a specific casino
You can run most of these checks in ten minutes before depositing, using the casino's footer, a game's info panel and the regulator's website.
- Find the licence number and the issuing regulator, then search the regulator's public register for the number and the exact domain you are on.
- Note which studios supply the games. Recognised studios bring their own lab certification, while unknown ones deserve more caution.
- Open a few games and read the info panel. A certified game shows its rules and theoretical RTP.
- Look for named test labs and click through. A badge that does not link to a certificate for that operator or game proves little.
- If the casino has originals, find the fairness page, set your own client seed, play a few small bets, rotate the seed and verify one result.
- Read the terms for "malfunction voids all pays" and for how game disputes are handled, including deadlines and the named dispute body.
- Check the payout record in independent reviews. Fair games are worth little if withdrawals stall.
A fair game can still cost more than you meant to spend, so set a deposit limit before you play. For the wider set of criteria, from bonuses to payout speed, see how to choose a crypto casino.
Frequently asked questions
Who tests slot games at crypto casinos?
The studio that makes the slot sends it to an independent lab such as GLI, iTech Labs, eCOGRA or BMM before release. The lab tests the RNG, the maths and the code. The crypto casino offers the certified game but usually does not run its random number generator.
Is provably fair better than an RNG certificate?
They check different things. Provably fair lets you confirm a single result was not changed after your bet. A lab certificate confirms the whole game's maths and randomness were tested before release, which no individual player can do. The strongest set-up has both.
Can a crypto casino change a slot's RTP?
Not the maths of a certified third-party slot on its own, since the studio builds and hosts the game. The casino does choose which games to offer, so read the RTP in the game's info panel rather than relying on a figure from a review.
How can I tell if a casino's fairness badge is real?
Click it. A genuine seal links to a certificate or register entry on the lab's or regulator's own website, naming the operator or the game. A static image with no link, or a link back to the casino's own page, proves nothing.
What should I do if I think a game result was wrong?
Save the bet ID, time and screenshots, and complain to the casino in writing straight away. Under Anjouan's rules, for example, game outcome disputes have to reach the operator within 14 days, and unresolved ones can go to the dispute resolution provider named in the casino's terms.