iGaming Glossary: 120+ Casino and Slot Terms Explained in Plain English

This iGaming glossary covers 250+ terms used across slots, casino bonuses, live dealer, sportsbook, responsible gambling, and the operator/platform stack — all in plain English with links to SlotDecoded’s deep-dive guides. Whether you are a player trying to understand wagering requirements, a bonus hunter decoding session stats, or a reviewer writing about RTP and volatility, this iGaming glossary gives you the accurate definition in one place. Bookmark it — every term links back to the relevant guide where it is explained in full.

A

243 Ways / 1,024 Ways

A ways-to-win mechanic where matching symbols pay in any position on adjacent reels. 243 ways uses 5 reels × 3 rows. 1,024 ways uses 5 × 4. No fixed paylines — every adjacent combination counts.

A/B Test

Operator technique that shows different versions of a page, bonus, or CTA to different user segments, measuring which performs better. Common in CRM and bonus optimisation.

Accumulator (Acca)

A sportsbook bet combining multiple selections. All must win for the bet to pay. Higher potential payout, lower probability.

Acquisition

The process of attracting new players to a casino — through affiliates, paid ads, SEO, or promotions like no deposit bonuses.

Affiliate

A third party that refers players to a casino in exchange for revenue share or CPA (cost per acquisition). SlotDecoded is an affiliate site.

Aggregator

A platform that integrates games from multiple providers into a single API, allowing operators to offer thousands of games without individual provider contracts. Examples: EveryMatrix, SoftSwiss.

AML (Anti-Money Laundering)

Regulatory requirements that force operators to monitor transactions, report suspicious activity, and verify the source of player funds. Tied to licensing conditions.

Ante Bet / xBet

An optional increased stake (usually 25%–100% extra) that improves the probability of triggering a bonus round. Does not guarantee a trigger — just improves the odds. See how slot features affect RTP.

API (Application Programming Interface)

The technical interface through which games, payment systems, and platform components communicate. Operators connect providers via API.

Autoplay

A feature that spins automatically for a set number of spins at a fixed bet. Restricted or banned in some jurisdictions (UK limits autoplay with loss/win stops).

Avalanche / Cascade Reels

A mechanic where winning symbols are removed and new symbols fall into place, allowing consecutive wins from a single spin. Used in Gates of Olympus, Gonzo’s Quest, and most Nolimit City games.

B

B2B / B2C

B2B (business-to-business): providers selling to operators. B2C (business-to-consumer): operators selling to players.

Back Office

The operator-side admin panel for managing players, bonuses, compliance, payments, and reporting.

Balance (Cash / Bonus)

Your account holds two balances: real cash (withdrawable) and bonus funds (subject to wagering requirements). Which is used first depends on sticky vs non-sticky structure.

Bankroll

The total amount of money a player has allocated for gambling. The Responsible Gambling Planner calculates a sustainable bankroll from disposable income.

Base Game

The standard spinning mode of a slot — everything outside bonus rounds and free spins. In high-volatility games, the base game contributes 15–40% of total RTP; the rest comes from features. See how features affect RTP.

Bet Size / Stake

The amount wagered per spin or per round. During bonus wagering, bet size is capped by the max bet rule.

Bonus Buy / Feature Buy

A mechanism that lets you pay a lump sum (typically 60×–500× bet) to skip the base game and enter the bonus round directly. See bonus buy slots. Banned in the UK.

Bonus Hunt

A session format where a player buys multiple bonus rounds across different slots, opens them later in sequence, and tracks the total ROI. See what is a bonus hunt and the Bonus Hunt Tracker.

Bonus-Only Wagering

Wagering requirement applies only to the bonus amount, not your deposit. Much cheaper to clear than D+B (deposit + bonus) wagering.

Break-Even Multiplier

In a bonus hunt, the average multiplier across all buys needed to recover the total cost. Calculated as total cost ÷ total bet value of all buys.

Bust Probability / Risk of Ruin

The probability that your bankroll reaches zero before the session completes. Model it with the Session Risk Analyzer.

C

Cashback

A percentage of net losses returned to the player — best when wager-free (0× WR). See reload bonus vs cashback.

Casino Bonus

Any promotional incentive — deposit match, free spins, cashback, reload, or no deposit. See the casino bonuses guide for all 8 types ranked by value.

Chargeback

A player disputes a card transaction with their bank. Operators treat excessive chargebacks as fraud indicators.

Cluster Pays

A win mechanic where matching symbols in connected clusters (horizontally/vertically adjacent) pay instead of traditional paylines. See cluster pays explained.

Cold Slot / Hot Slot (Myth)

The false belief that slots cycle between “hot” (due to pay) and “cold” (avoiding payouts) phases. Every spin is independent. See hot and cold slots debunked.

Compliance

The regulatory, legal, and ethical obligations an operator must meet — AML, KYC, responsible gambling, advertising standards, data protection. Tied to licence conditions.

Contribution Rate / Game Weight

The percentage of a wager that counts toward clearing wagering requirements. Slots: usually 100%. Blackjack: 0–20%. See game contribution rates.

CPA (Cost Per Acquisition)

An affiliate payment model where the affiliate receives a one-time fee for each player who deposits. Alternative to revenue share.

Crash Game

A provably fair game where a multiplier rises from 1× until it “crashes” at a random point. Players cash out before the crash to win. See crash games explained.

CRM (Customer Relationship Management)

The system operators use to segment players, trigger promotions, manage retention, and personalise communication.

Cryptocurrency Casino

An operator accepting Bitcoin, Ethereum, or other crypto for deposits and withdrawals. Often operates under lighter regulation.

D

D+B Wagering (Deposit + Bonus)

Wagering requirement applies to both your deposit and the bonus — roughly doubling the clearing cost compared to bonus-only wagering. See bonus-only vs D+B wagering.

Dead Spin

A spin that returns zero — no win at all, not even a partial return. Higher-volatility games produce more dead spins. Related to hit rate.

Demo Mode / Play for Fun

A free version of a slot using virtual credits. Uses the same RNG and RTP as the real-money version (required by regulation).

Deposit Bonus / Welcome Bonus

A casino matches your deposit with bonus funds — e.g., 100% up to €500. Subject to wagering requirements. See the casino bonuses guide.

Deposit Limit

A responsible gambling tool that caps how much you can deposit per day, week, or month. Set it using the Responsible Gambling Planner.

Disconnection Policy

Rules governing what happens to an in-progress spin or bet if your internet connection drops. Regulated casinos must complete the round and credit the result.

Drops & Wins

A Pragmatic Play network promotion where random cash prizes drop during qualifying games. Daily and weekly prize pools funded by the provider.

E

eCOGRA / GLI / BMM / iTech Labs

Independent testing agencies that audit RNG integrity, RTP accuracy, and game fairness for regulators.

EV (Expected Value)

The mathematically expected long-run result of a bet or bonus. EV = (Win Probability × Win Amount) − (Loss Probability × Stake). A positive-EV bonus is worth claiming. The Wager Bonus Calculator computes bonus EV.

eWallet

A digital payment method (Skrill, Neteller, MuchBetter, PayPal) used for casino deposits and withdrawals. Often excluded from bonus eligibility.

Expanding Symbol / Expanding Wild

A symbol that grows to cover an entire reel when it appears, creating additional win combinations.

Expiry (Bonus)

The deadline to use a bonus and complete wagering requirements. Typically 7–30 days. Missing the expiry forfeits the bonus and associated winnings.

F

Feature Frequency

How often a bonus round triggers — expressed as 1-in-X spins. A 1-in-150 feature frequency means you trigger the bonus once per 150 spins on average.

Feature Gamble

A post-trigger option to gamble your bonus round for a higher-tier version (e.g., gamble for more free spins or a multiplier upgrade). Win = upgrade. Lose = forfeit the bonus entirely.

Fixed Jackpot

A jackpot with a predetermined payout amount (e.g., 1,000× bet). Does not grow with play — contrasts with progressive jackpots.

Floor Game (Bonus Hunt)

A low-to-medium volatility slot used to sustain bankroll during a bonus hunt. Part of the 3-layer framework (floor / backbone / moonshot).

Free Spins

Bonus rounds where you spin without deducting from your balance. Can be part of a slot feature (in-game) or a casino promotion (e.g., 50 free spins on deposit). Promotional free spins usually have wagering on winnings.

FTD (First-Time Depositor)

A player who has just made their first deposit. The FTD conversion rate is a key operator acquisition metric.

G

Gamble Feature

A post-win option to risk your winnings in a 50/50 gamble (typically red/black card or coin flip). Win = double. Lose = forfeit. Does not change RTP.

Gamification

Adding game-like elements (levels, achievements, leaderboards, missions) to the casino experience to increase engagement and retention.

GAMSTOP

The UK’s national self-exclusion scheme. Registering blocks access to all UKGC-licensed gambling sites for 6 months, 1 year, or 5 years. See take a break.

GGR (Gross Gaming Revenue)

Total stakes minus total payouts. The operator’s gross income from gambling before bonuses, taxes, and adjustments. GGR = Stakes − Payouts.

Grid Slot

A slot using a grid layout (e.g., 7×7) with cluster pays instead of reels and paylines. Examples: Reactoonz, Jammin’ Jars.

H

Handle

Total amount staked (wagered) across all bets. Not the same as deposits — a €100 deposit wagered 30× generates €3,000 in handle.

High Roller / VIP

A player who deposits and wagers significantly above average. Eligible for high roller casino bonuses with elevated caps and negotiable terms.

Hit Frequency / Hit Rate

The percentage of spins that produce any win (including wins below bet size). A 25% hit rate means 1 in 4 spins returns something. See slot hit rate explained.

Hold

The percentage of handle the casino retains. Hold = Handle − Payouts. Related to but different from house edge (which is theoretical, while hold is actual).

Hold & Win / Respin Feature

A mechanic where triggering symbols lock in place and remaining positions respin for a set number of respins (usually 3). Collecting symbols add values; filling the grid awards a grand prize.

House Edge

The mathematical advantage the casino has on every bet. House edge = 100% − RTP. A 96% RTP game has a 4% house edge. See house edge in slots.

I

iGaming

The online gambling industry — covering slots, casino, live dealer, sportsbook, poker, bingo, and lottery operated via the internet.

In-Game RTP / Observed RTP

The actual RTP measured over a specific sample of spins — can deviate significantly from theoretical RTP in the short term due to volatility.

In-Play Betting / Live Betting

Sportsbook betting placed during an event in progress, with odds updating in real time.

J

Jackpot (Local / Network / Progressive)

A prize pool above standard wins. Local jackpots are funded by one game. Network jackpots pool contributions across multiple casinos. Progressive jackpots grow with every bet until won. See jackpots in slots.

Jurisdiction

The regulatory territory that governs an operator’s licence — e.g., Malta (MGA), UK (UKGC), Gibraltar, Isle of Man, Curaçao. See iGaming licences explained.

K

KPI (Key Performance Indicator)

Metrics operators track: GGR, NGR, FTD count, conversion rate, churn rate, ARPU (average revenue per user), LTV (lifetime value).

KYC (Know Your Customer)

Identity verification required by regulators before a player can withdraw — photo ID, proof of address, sometimes source of funds. Complete it immediately after registering.

L

LDW (Loss Disguised as Win)

A spin that returns less than the bet but is presented with winning sounds and animations. Example: bet €1, win €0.30 — the game celebrates, but you lost €0.70. See player psychology.

Line Bet

The amount wagered per payline. Total bet = line bet × number of active paylines.

Live Casino

Real dealers streaming table games (blackjack, roulette, baccarat, game shows) from a studio. Players bet via a digital interface. Major providers: Evolution, Pragmatic Play Live.

Loss Stop

A self-imposed limit: if you lose X amount in a session, you stop playing. Set it with the Responsible Gambling Planner.

M

Max Bet Rule

The maximum bet size allowed while clearing wagering requirements — typically €5/spin. Exceeding it can void the bonus and all winnings. See max bet rule explained.

Max Cashout / Max Win Cap

The maximum amount you can withdraw from bonus winnings. Common on no deposit bonuses (€20–€100). See max cashout explained.

Max Win (Slot)

The highest possible payout from a single spin, expressed as a multiple of bet size (e.g., 10,000×). See max win explained and highest max win slots ranked.

Megaways™

A Big Time Gaming mechanic licensing variable reel sizes (2–7 symbols per reel), creating up to 117,649 ways to win. High volatility, variable hit rate. See Megaways vs classic slots.

Moonshot (Bonus Hunt)

A high-volatility, high-max-win slot used in a bonus hunt for upside potential. Part of the 3-layer framework.

Multiplier

A value that multiplies your win — e.g., a 5× multiplier on a €2 win pays €10. Multipliers can be applied per spin, per cascade, or accumulate across a bonus round.

Must-Drop Jackpot

A jackpot guaranteed to drop before a specific time or amount. Adds urgency — the EV improves as the deadline approaches.

Mystery Symbol

A symbol that appears on the reels and then reveals itself as a random matching symbol, creating additional win combinations.

N

Near Miss

When two jackpot symbols land on the payline and the third stops one position away. Creates the illusion of “almost winning” — a psychological design pattern, not a prediction of future results.

NGR (Net Gaming Revenue)

GGR minus bonuses, adjustments, and chargebacks. NGR = GGR − Bonuses − Adjustments. The revenue figure operators actually report.

No Deposit Bonus

A small bonus (€5–€25 or 10–100 free spins) given for registering without depositing. High WR, low max cashout. See no deposit casino bonus guide.

No Wagering Bonus / Wager-Free

A bonus where winnings are paid as real cash with 0× WR. The most player-friendly bonus type — but other restrictions still apply. See no wagering bonus.

Non-Sticky Bonus (Forfeit / Parachute)

A bonus structure that uses your real money first. If you win before touching the bonus, you can withdraw and forfeit the bonus — keeping profit. Opposite of sticky. See sticky vs non-sticky.

Nudge

A mechanic where a reel shifts up or down by one symbol after landing to complete a winning combination.

O

Operator

The company that runs a casino or sportsbook — holds the licence, manages the platform, and is responsible for player funds and compliance.

OBS Overlay

A streaming overlay that displays live session data (bonus hunt results, balance, ROI) on stream. The Bonus Hunt Tracker includes an OBS overlay URL.

P

P10 / P50 / P90

Percentile outcomes from simulation. P10 = worst 10% scenario. P50 = median (most likely). P90 = best 10%. Used by the Session Risk Analyzer.

PAM (Player Account Management)

The core operator platform managing player accounts, wallets, bonuses, KYC, and regulatory reporting.

Pay Both Ways / Win Both Ways

A slot that pays winning combinations from left-to-right and right-to-left, effectively doubling potential payline wins.

Payline

A predefined line across the reels where matching symbols must land to create a win. See paylines explained.

Payout Speed

How long a casino takes to process a withdrawal — from request to funds in your account. Track it with the Withdrawal Speed Tracker.

Paytable

The in-game reference showing symbol values, win combinations, bonus rules, and RTP. Always check the paytable before playing a new game.

PGSI (Problem Gambling Severity Index)

A clinically validated 9-question screening tool that assesses gambling risk. Integrated into the Responsible Gambling Planner.

Progressive Jackpot

A jackpot that grows with every bet placed on the game (or network of games) until one player wins it. Resets to a seed value after being won.

Provably Fair

A cryptographic system (common in crypto casinos) that lets players verify each bet’s outcome was not manipulated. Uses server seed + client seed + nonce.

Provider / Studio

The company that develops and supplies slot games — e.g., Nolimit City, Pragmatic Play, Hacksaw Gaming, NetEnt, Play’n GO.

Q

Qualifying Deposit / Qualifying Wager

The minimum deposit or wager required to activate a bonus or meet promotion conditions.

R

Reality Check

A responsible gambling feature that pauses play at set intervals (e.g., every 60 minutes) and shows time played and net balance. Required by UKGC.

Reels / Rows

The vertical columns (reels) and horizontal positions (rows) that form the slot grid. A 5×3 slot has 5 reels and 3 rows.

Reload Bonus

A recurring deposit match for existing players (e.g., 50% up to €100 weekly). See reload bonus vs cashback.

RGS (Remote Game Server)

The server-side infrastructure that hosts game logic, RNG, and math models. Operators connect to an RGS via API to offer a provider’s games.

RNG (Random Number Generator)

The algorithm that determines every spin outcome. Produces statistically random results verified by independent testing labs. See how RNG works.

ROI (Return on Investment)

In bonus hunting: total bonus payouts ÷ total bonus costs. An ROI of 1.5× means you got 50% more back than you invested.

Rolling Reserve

A percentage of operator revenue held by the payment processor as a risk buffer — typically 5–10% for 90–180 days.

RTP (Return to Player)

The percentage of total wagered money a slot returns to players over millions of spins. A 96% RTP means the game retains 4% as house edge. See RTP guide. Check the Volatility & RTP Calculator to see what RTP means per session.

S

Scatter Symbol

A special symbol that triggers bonus features (usually free spins) regardless of payline position. Typically needs 3+ scatters to activate. See scatter symbols explained and slot symbols guide.

Seed (RNG)

The initial value fed into the RNG algorithm that starts the random sequence. See seed in slot games.

Self-Exclusion

A formal process where a player blocks themselves from gambling for a set period. See take a break.

Session

A defined period of play — from opening a game to closing it or cashing out. Track sessions with the Win Per Session Tracker.

Sticky Bonus

A bonus structure that locks withdrawals until full wagering is cleared. Less player-friendly than non-sticky.

Sticky Wild

A wild symbol that remains in position for subsequent spins or cascade rounds, creating additional win opportunities.

Streamer

A content creator who broadcasts live gambling sessions on platforms like Twitch or YouTube. See streamer profiles on SlotDecoded.

T

Tilt

An emotional state — typically frustration after losses — that leads to irrational decisions like increasing bets or chasing losses. Tag it in your session tracker notes.

Tournament (Slots)

A timed competition where players spin on a specific slot and compete for the highest score. Winners receive prizes from a pool.

Turnover / Wagering Volume

The total amount wagered — distinct from deposits. A €100 deposit wagered 30× = €3,000 turnover.

U

UKGC (UK Gambling Commission)

The regulatory body governing all gambling in Great Britain. One of the strictest licensing jurisdictions.

V

Variable RTP

Games shipped with multiple RTP configurations (e.g., 96.5%, 94.5%, 92.5%). The operator chooses which version to run — always check the in-game info panel. See RTP guide.

Volatility / Variance

How much session results deviate from the expected RTP. Low volatility = steady, small wins. High volatility = rare, large wins with long losing streaks. See slot volatility explained and the Volatility & RTP Calculator.

W

Wagering Requirement (WR)

The number of times you must wager a bonus before withdrawing. A €100 bonus at 30× = €3,000 total wagers. See wagering requirements explained and the Wager Bonus Calculator.

Ways to Win

A mechanic replacing fixed paylines — matching symbols on adjacent reels in any position count as a win. See ways to win and cluster pays & expanding reels.

White-Label / Turnkey

A ready-made casino platform an operator can launch under their own brand with minimal setup. The platform provider handles tech, licensing, and payments.

Wild Symbol

A symbol that substitutes for other symbols to complete winning combinations. Does not usually replace scatters or bonus symbols. See slot symbols guide.

Win-Stop

A self-imposed limit: if you reach X profit in a session, you stop playing and cash out. Protects winnings from being given back. Set it with the Responsible Gambling Planner.

Withdrawal Pending

The period between requesting a withdrawal and the casino processing it. During this window, some casinos allow you to reverse the withdrawal — a dangerous dark pattern.

X

X-iter™

An ELK Studios mechanic offering multiple buy-in levels for the same slot — from a free bonus-chance mode to direct feature buys at increasing cost/reward tiers.

xWays / xNudge / xSplit / xBomb / xRip

Nolimit City proprietary mechanics that modify reels during play. xWays expands symbol count, xNudge adds multipliers on nudge, xSplit doubles symbols, xBomb destroys blockers. See how features affect RTP.

Y

Yield (Sportsbook)

The profit margin the bookmaker builds into odds — analogous to house edge in slots.

Z

Zero-Margin Bet

A promotional sportsbook bet with no built-in margin — effectively 100% RTP. Used as an acquisition tool.