Reference

iGaming glossary — 105 terms, defined plainly

The vocabulary operators, developers and compliance teams actually need — game math, RNG and fairness, certification, wallet and custody, and the commercial models that sit on top. No marketing definitions.

Glossary

Platform & commercial

TermDefinition
iGamingUmbrella term for online gambling — casino, sportsbook, poker and lottery — and the business-to-business technology industry that supplies it.
OperatorThe licensed business that runs a casino brand, holds the gambling licence, owns the player relationship and is accountable to the regulator.
Supplier / providerA business-to-business company that licenses technology or game content to operators. A supplier does not hold a gambling licence on the operator's behalf.
White-label casinoA model where an operator launches under its own brand on a supplier's platform. The operator controls the brand and marketing; the supplier provides games, wallet and back office.
Turnkey casinoA more complete package than white-label, typically including the platform plus assistance with licensing, payments and operations. The operator still holds its own licence.
Remote Gaming Server (RGS)The server that runs game logic: it holds the RNG, resolves every bet server-side, applies the configured RTP model and persists the round. The browser only renders results the RGS has already decided.
Game aggregatorA middle layer that resells access to many game studios through one integration, taking a share of revenue on rounds routed through it, on top of the originating studio's share.
Player Account Management (PAM)The system of record for players: registration, identity, balances, bonuses, responsible-gambling limits, and the transaction history a regulator will ask to see.
Seamless walletAn integration model where the game server calls the operator's own wallet for balance, debit and credit on every bet, so the operator keeps a single source of truth for money.
Transfer walletAn older model where funds are moved into a game-provider wallet before play and back afterwards. Simpler to build, worse for reconciliation and player experience.
Multi-tenantOne platform instance serving many operators with strict data isolation between them — typically enforced at the database level rather than in application code alone.
GGR (Gross Gaming Revenue)Total player wagers minus total player winnings, before deducting bonuses, taxes or fees. The most common base for revenue-share agreements.
NGR (Net Gaming Revenue)GGR minus deductions such as bonus costs, payment fees and gaming taxes. Closer to what the operator actually keeps.
Revenue shareA commercial model where the supplier is paid a percentage of GGR or NGR rather than a fixed fee. Standard in iGaming, and stackable when several layers sit between operator and game.
Hold percentageThe share of total wagered money the operator retains over time — the practical inverse of RTP, observed rather than theoretical.
SandboxA non-production environment mirroring live behaviour, used for integration and QA. A good sandbox supports forced outcomes so testers can trigger specific results deliberately.
Go-liveThe point at which an integration begins accepting real-money play, normally after sandbox sign-off, webhook verification and any required regulatory approval.
Glossary

Game math

TermDefinition
RTP (Return to Player)The percentage of total wagered money a game is designed to return to players over a very large number of rounds. A 96% RTP game returns 96 units per 100 wagered in the long run — not within any single session.
Theoretical RTPThe RTP calculated analytically from the game's math model and paytable. This is the figure a testing laboratory verifies.
Actual RTPThe RTP observed in live play. It converges towards theoretical RTP as volume grows, and deviation alerts on this figure are a standard monitoring control.
Volatility / varianceHow widely outcomes disperse around the average. Low volatility pays small amounts often; high volatility pays rarely but larger. Two games can share an RTP and feel completely different.
Hit frequencyThe proportion of rounds that return any win at all, independent of size. A key lever on how a game feels to play.
Max winThe largest payout a single round can produce, expressed as a multiple of the bet and enforced server-side so it cannot be exceeded by any combination of features.
PaytableThe table mapping winning combinations to payouts. Together with reel composition it determines the game's theoretical RTP.
PaylineA defined path across the reels on which matching symbols pay. A 20-payline game evaluates twenty such paths on every spin.
Reel stripThe ordered list of symbols on each reel. Reel composition, far more than the paytable alone, drives a slot's volatility.
WildA symbol that substitutes for other paying symbols to complete combinations.
ScatterA symbol that pays regardless of payline position and typically triggers a feature such as free spins.
Free spinsA feature round awarded by a trigger condition, played without deducting further stake from the player's balance.
RetriggerAwarding additional free spins from inside an active free-spins round, extending the feature within the same round.
MultiplierA factor applied to a win or to an accumulating value. In crash and ladder formats, the rising multiplier is the core mechanic rather than a bonus.
Math modelThe written specification of a game's probabilities, paytable and features, from which theoretical RTP is derived. Testing laboratories review the model, not just the software.
Monte Carlo simulationRunning a game's math over millions of simulated rounds to verify that observed RTP matches the theoretical model. Fixed-seed runs make the result reproducible by a third party.
House edgeThe complement of RTP — the share of wagered money the game is designed to retain. A 96% RTP game has a 4% house edge.
Bet levelThe stake configuration available to the player. Bet limits are frequently constrained per jurisdiction by the compliance engine.
Glossary

Game formats

TermDefinition
Video slotThe dominant online casino format: a reel grid with paylines, wilds, scatters and feature rounds. Single-step — the player commits a stake and the round resolves at once.
Crash gameA session format where a multiplier rises while the round is live and the player chooses when to cash out. Holding longer increases the payout; holding too long ends the round with nothing.
Cash-out gameBroader term for any format where the player's decision to stop determines the payout, including crash and ladder variants.
Mines gameA pick-and-reveal format where the player uncovers tiles for escalating multipliers, with hidden losing tiles that end the round. Bank at any point or continue.
Ladder / tower gameA multi-step climb where each successful step raises the multiplier and the risk, with cash-out available at every rung.
Instant gameShort-round, quickly-understood casino formats — crash, mines, ladder, dice, arcade — as distinct from slots and table games. Also called originals or turbo games.
Arcade casino gameAn instant game with a skill-flavoured interaction layer, such as aiming or timing, sitting on top of a simulated math model that determines the distribution of outcomes.
Single-step gameA game where one player action resolves the entire round.
Multi-step gameA game where the round advances through several player decisions, each of which can end it.
Demo modePlay with simulated credit and no real-money stake, used for marketing, evaluation and in some jurisdictions required before registration.
Glossary

RNG & fairness

TermDefinition
RNG (Random Number Generator)The component producing the unpredictable values that determine game outcomes. In regulated gambling it must be cryptographically secure, statistically tested and server-side.
PRNGA pseudorandom number generator — deterministic given its seed. Adequate for simulation, not for money, unless it is cryptographically secure.
CSPRNGA cryptographically secure PRNG: computationally infeasible to predict future outputs or recover past ones from observed values. The required class for real-money gaming.
HMAC-DRBGA deterministic random bit generator built on HMAC, specified in NIST SP 800-90A. Slotty Labs' RNG uses HMAC-DRBG with SHA-512 at 256-bit security strength.
NIST SP 800-90AThe US standard specifying approved deterministic random bit generator constructions, including HMAC-DRBG. The reference point most testing laboratories expect an RNG design to cite.
NIST SP 800-22A statistical test suite for evaluating randomness. Run continuously in production, it detects an RNG degrading over time rather than only at certification.
Entropy sourceThe unpredictable physical or system input that seeds an RNG. Multi-source entropy avoids depending on any single source behaving correctly.
SeedThe initial value from which a deterministic generator produces its output sequence. In provably-fair schemes the seed is the object that gets committed and later revealed.
Provably fairA scheme letting a player verify independently that an outcome was not altered after their bet, without trusting the operator — normally via cryptographic commit-reveal.
Commit-revealThe mechanism behind provable fairness: the server publishes a hash of its seed before the bet, then reveals the seed afterwards. The player checks the hash matches and recomputes the outcome.
Server seedThe secret value the server commits to before a round and reveals afterwards.
Client seedA value contributed by the player, mixed with the server seed so the server cannot choose an outcome unilaterally.
NonceA per-round counter combined with the seeds, so a single seed pair generates a distinct, verifiable outcome for every round.
Event sourcingStoring a round as the ordered sequence of events that produced it rather than only its final state, so the round can be reconstructed exactly.
Deterministic replayRe-running a stored round from its event log and obtaining precisely the original result — the practical basis for dispute resolution and laboratory review.
Glossary

Compliance & certification

TermDefinition
GLI-19Gaming Laboratories International's standard for Interactive Gaming Systems, covering RNG, game fairness, player account handling, and system security and integrity. The most widely cited reference for online casino platforms.
GLI-11GLI's standard for gaming devices, frequently referenced alongside GLI-19 for game-level requirements.
Testing laboratoryAn accredited independent body that reviews gaming systems against a standard and issues certification. Examples include GLI, BMM Testlabs and eCOGRA.
CertificationA laboratory's formal attestation that a specific system version meets a named standard, normally scoped to a market and a submission. Certification is completed per market, not held generically.
Certification-readyA system built to a standard's requirements with the evidence package assembled in advance, so laboratory review can begin quickly. Distinct from being certified.
Jurisdiction engineThe runtime component enforcing a market's rules — bet limits, mandatory messaging, session controls, permitted features — as configuration rather than as forked code.
Curaçao eGamingA long-established and comparatively accessible licensing jurisdiction, restructured under the Curaçao Gaming Authority. Common first market for new operators.
MGA (Malta Gaming Authority)Malta's regulator, widely regarded as a tier-one European licence with substantial technical and reporting requirements.
UKGC (UK Gambling Commission)The Great Britain regulator, among the most demanding globally, with strict rules on responsible gambling, affordability and advertising.
AnjouanA licensing jurisdiction in the Comoros that has grown as an entry-level alternative to Curaçao.
Responsible gamblingTooling and policy protecting players from harm: deposit and loss limits, session limits, reality checks, self-exclusion and time-outs. Mandatory in every serious jurisdiction.
Self-exclusionA player-initiated block on their own access for a defined period, which the operator must enforce and must not circumvent through marketing.
Reality checkA periodic interruption telling the player how long they have been playing and what they have staked.
KYC (Know Your Customer)Identity verification on players, required before withdrawal in most jurisdictions and often at registration or at defined thresholds.
AML (Anti-Money Laundering)Controls detecting and reporting suspicious financial activity, including transaction monitoring and source-of-funds checks.
Audit trailAn immutable record of what happened and who did it. Hash-chaining makes it tamper-evident; WORM storage makes it non-erasable.
WORM storageWrite Once, Read Many — storage that cannot be modified after writing, used for records that must survive an attempt to alter them.
Merkle anchoringPublishing a Merkle root of a log to an external system so the log's state at a point in time can be proven later.
SBOMA Software Bill of Materials — a machine-readable inventory of components and dependencies, increasingly requested during laboratory review. CycloneDX is a common format.
Glossary

Wallet & crypto custody

TermDefinition
Double-entry ledgerAccounting where every transaction posts equal debits and credits, so the books balance by construction and a missing entry is structurally visible.
Hash chainLinking each ledger entry to a hash of the previous one, so any retroactive edit breaks the chain and becomes detectable.
Idempotency keyA unique identifier on a money operation ensuring a retried request produces exactly one posting — the standard defence against double-charging on network retries.
Pessimistic lockingLocking a balance row for the duration of a transaction so concurrent operations cannot race it into a negative balance.
ReconciliationSystematically checking that the ledger agrees with external reality — cached balances, payment processors, and for crypto, on-chain holdings.
Minor unitsRepresenting money as whole numbers of the smallest denomination (cents, satoshis) rather than decimals, eliminating floating-point rounding drift from the money path.
HD walletA hierarchical deterministic wallet deriving unlimited addresses from one seed, letting a platform assign each player unique deposit addresses without storing separate keys.
SweepingAutomatically consolidating funds from many player deposit addresses into managed storage, including handling amounts too small to move economically.
Sponsored gasThe platform paying network transaction fees so a player does not need a native-token balance to move a stablecoin. Per-tenant budgets prevent fee spikes becoming unbounded cost.
HSM / KMSHardware Security Module and Key Management Service — systems holding cryptographic keys so that keys are used without ever being exposed as loose material.
Cold storageKeys kept offline, out of reach of any internet-connected system, normally for the majority of reserves.
MultisigRequiring several independent keys to authorise a transaction, so no single person or compromised machine can move funds alone.
Solvency verificationContinuously checking that on-chain holdings cover player obligations per currency and per tenant — the crypto equivalent of proving segregated player funds.
StablecoinA cryptocurrency designed to hold a stable value against a reference asset, typically the US dollar. USDT and USDC dominate iGaming deposits.
Glossary

Integration & security

TermDefinition
SDKA software development kit packaging a platform's API into idiomatic code. Slotty Labs ships an official TypeScript SDK with zero runtime dependencies for Node 18+.
Launch tokenA short-lived, single-use credential authorising one game session. Slotty Labs uses RS256-signed tokens valid for thirty seconds.
RS256RSA signature with SHA-256, an asymmetric scheme letting a recipient verify a token's authenticity using only a public key.
SSO (Single Sign-On)Carrying an authenticated identity across systems so a player moves from operator site to game without a second login.
WebhookAn HTTP callback the platform sends when an event occurs, so the operator learns about outcomes without polling.
HMAC-SHA256 signingSigning webhook payloads with a shared secret so the recipient can verify the message is authentic and unmodified.
Dead-letter queueWhere events land after delivery retries are exhausted, so a receiver outage delays events rather than losing them.
Forced outcomeA sandbox facility letting QA specify a result deliberately — a max win, a bust, a disconnect — instead of waiting for probability.
Row-level securityDatabase-enforced access rules restricting which rows a query can see, used to make tenant isolation a property of the database rather than of application code.
RBACRole-Based Access Control — permissions granted by role rather than per individual, so administrative access is auditable and revocable.
MFAMulti-Factor Authentication — requiring more than a password. TOTP apps and WebAuthn passkeys are the standard second factors for operator back-office accounts.
WebAuthn / passkeysA phishing-resistant authentication standard using device-bound cryptographic keys instead of shared secrets.
FAQ

Most-asked definitions

What does RTP mean in an online casino game?

RTP, or Return to Player, is the percentage of total wagered money a game is designed to return over a very large number of rounds. A 96% RTP game returns 96 units per 100 wagered in the long run — it says nothing about any single session.

What is the difference between an RGS and a PAM?

The RGS runs game logic and decides outcomes. The PAM is the system of record for players — identity, balances, bonuses and limits. An operator needs both; they can come from the same supplier or from different ones.

What does 'provably fair' actually prove?

That the outcome was fixed before you bet and was not changed afterwards. The server publishes a hash of its seed in advance and reveals the seed after the round, so you can check the hash and recompute the result yourself. It does not prove the game's RTP — that comes from the math model and simulation evidence.

Is 'certification-ready' the same as certified?

No. Certification-ready means the system is built to a standard's requirements and the evidence package is assembled so laboratory review can start quickly. Certification is the laboratory's formal attestation, completed per market as part of an operator's submission.

Still translating a spec into a decision?

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