Casino Terminology Glossary: House Edge, RTP, Variance, and More

What is a Casino Terminology Glossary (House Edge, RTP, Variance)?

Definition: the core math terms behind casino games

A casino terminology glossary gives you the key numbers that control long term cost and short term swings.

These terms describe how a game pays, how often it pays, and how rough the ride feels while you play.

• House edge. The casino’s average cut per bet, shown as a percent. A 2% house edge means you lose about $2 per $100 wagered over the long run.
• RTP (return to player). The flip side of house edge. RTP = 100% minus house edge, when both use the same rules and bet type.
• Variance (volatility). How widely results swing around the average. High variance means bigger up and down streaks, even if the RTP stays the same.
• Expected value (EV). Your long run average result per bet. Negative EV means the game costs you money over time.

For a deeper odds breakdown, see How Casino Game Odds Work: House Edge, Probability, and Payouts.

How these metrics connect: expected value, payouts, bankroll impact

House edge and RTP tell you the long run price of a game.

Variance tells you how your bankroll can swing before the long run shows up.

• Same RTP, different experience. Two slots can both list 96% RTP. The high variance slot may pay less often but in larger hits. The low variance slot may pay more often but in smaller hits.
• Bet size controls your loss rate. Your expected loss scales with total amount wagered. More spins or hands per hour, or higher stakes, increases expected loss at the same edge.
• Rules and bet types change the edge. In table games, the main game can have a low edge while side bets run much higher.

RTP helps you compare slots fast. Use it with game volatility and your budget. See RTP Explained: How to Use Return to Player to Choose Slots.

These numbers also protect you from bad logic like “due” outcomes. See Casino Myths vs Facts: Hot Streaks, “Due” Numbers, and Luck Explained.

Where you’ll see these terms: slots, blackjack, roulette, live casino

• Slots. RTP often appears in the help screen or rules. Volatility sometimes appears as low, medium, or high. Some providers hide it. Always treat RTP as a long run average, not a promise for your session.
• Blackjack. House edge depends on rules and your decisions. Table limits, dealer stands or hits on soft 17, and surrender rules all matter. Basic strategy lowers the edge. Side bets usually raise it.
• Roulette. House edge depends on wheel type. European roulette has a lower edge than American because it has one less zero. Your bet choice changes variance, not the wheel’s edge.
• Live casino. The game math stays the same, but speed changes your hourly exposure. More rounds per hour means you cycle more money through the edge.

If you want the simplest games to start with while you learn these terms, see Best Casino Game for Beginners: The Easiest Games to Learn First.

House Edge: Meaning, Why It Exists, and How to Compare Games

House Edge, What It Means

House edge is the casino’s long-run average profit from your bets, shown as a percentage.

If a game has a 2% house edge, you expect to lose $2 per $100 wagered over a large number of bets.

House edge measures the math of the game. It does not predict what happens in a short session.

House edge does not tell you how wild the swings feel. Variance controls that.

Why the House Edge Exists

Casinos build the edge into the rules and payouts.

• They set payouts slightly below true odds.
• They add rules that favor the dealer or the house.
• They use paytables that skim value from certain outcomes.

This is why the casino can offer games all day and still expect to profit.

For a deeper breakdown of how probability and payouts create edge, see How Casino Game Odds Work: House Edge, Probability, and Payouts.

House Edge vs Player Edge

Most casino games give you no control over the odds. The house edge stays fixed.

Some games let skill change outcomes. Your choices can reduce the house edge, or even flip it in rare cases.

• Blackjack. Correct strategy cuts the edge. Bad play raises it fast.
• Video poker. The paytable and your decisions drive your expected return.
• Sports betting. Prices and selection can create a player edge, but the sportsbook builds in margin.

Slots, roulette, baccarat, and most side bets do not reward skill. You pick a bet, then the math runs.

Examples, How Edges Compare

For slots, house edge and RTP connect directly. Higher RTP means lower house edge.

Use RTP to compare slots with the same volatility, see RTP Explained: How to Use Return to Player to Choose Slots.

Rule and Paytable Changes That Shift House Edge

Small rule changes can move the edge a lot. You need to check the table rules and paytable.

• Blackjack payouts. 3:2 beats 6:5. 6:5 adds a big extra edge for the house.
• Number of decks. Fewer decks usually helps you, all else equal.
• Dealer hits or stands on soft 17. Dealer stands helps you. Dealer hits helps the house.
• Double rules. Double on any two cards helps you. Limits help the house.
• Split rules. More resplitting options help you. No resplit or no double after split helps the house.
• Roulette zeros. One zero beats two zeros. Extra side bets usually carry higher edge.
• Slots paytables. Different RTP versions of the same title can exist. The casino chooses the setting.

Game providers build the math, casinos choose settings and rules where options exist. See Casino Game Providers Explained: Who Makes the Games (and Why It Matters).

Common Misconceptions That Cost You Money

Short sessions do not remove the edge. They only reduce how much you cycle through it.

Wins are not “due.” Independent games do not remember past results.

Luck does not change expected value. It only changes the path you take to the long-run average.

If you want a clean breakdown of streaks and “due” thinking, see Casino Myths vs Facts: Hot Streaks, “Due” Numbers, and Luck Explained.

RTP (Return to Player): What It Means, How It’s Set, and How to Find It

RTP definition, and what it really predicts

RTP means Return to Player. It is the long-run percentage a game pays back from total wagers.

If a slot has 96% RTP, the game returns about $96 for every $100 wagered over a very large number of spins. The other $4 is the average cost of playing.

RTP does not tell you what happens in a short session. Your results can sit far above or below the stated RTP for a long time.

RTP vs house edge, and when it is not 1:1

In many games, you can convert RTP to house edge with a simple rule.

House edge (%) = 100% - RTP (%).

Example. 96% RTP equals a 4% house edge.

This clean conversion fits most fixed-payout games, especially slots and many table games stated as a single RTP figure.

It stops being clean when the payout depends on your choices, your bet type, or rule sets. Blackjack, video poker, and some specialty bets can change RTP based on strategy and pay tables.

How RTP gets set, and who signs off on it

The game provider sets RTP options during game design. Many online slots ship with more than one RTP configuration.

Casinos pick which RTP version to run, if the jurisdiction and the provider allow it.

Testing labs verify the math model and the random number generator. Regulators approve games for a market and define what a casino can change.

• Provider defines the pay table, feature logic, and RTP variants.
• Test lab checks the RNG, the implementation, and the stated theoretical return.
• Regulator sets rules for disclosure, minimum returns, and permitted configurations.

Certification usually covers the RNG behavior, the payout rules, and that the game matches the approved math. It does not promise you will see the stated RTP in your session.

Where to find RTP in a real game

Check places the provider controls, not marketing banners.

• The in-game menu. Look for i, Help, Game Rules, or Paytable.
• The game info panel in the lobby, if the casino lists it.
• The casino help page for slots, if it lists RTP per title.

If you cannot find RTP in the game rules, treat it as unknown. Pick a game that shows it.

Online RTP vs land-based RTP

Online games often allow multiple RTP settings. Transparency depends on the market and the operator.

Land-based machines also use approved settings, but you rarely see a clear RTP label on the cabinet. Jurisdictions may publish minimum return rules, not per-machine RTP.

For online play, you can usually verify RTP inside the game rules. For land-based play, you often cannot.

Jackpots and pooled features, what RTP includes

RTP can include different parts of the payout, depending on the game.

• Base RTP covers normal wins from the base game and standard bonus rounds.
• Jackpot contribution diverts part of each bet into a jackpot fund.
• Total RTP may include the expected value of jackpots over the long run.

For network jackpots, the stated RTP may assume the jackpot gets won at a typical level over time. Your actual return depends on jackpot hit timing and current jackpot size.

When a game lists both numbers, compare games using the same type of RTP, either base only or total including jackpots.

What counts as a good RTP by game type

RTP varies by game and by bet. Use ranges as a filter, not a guarantee.

If you want the cleanest comparisons, use house edge rankings. See Which Casino Games Have the Best Odds? Ranked by House Edge and How Casino Game Odds Work: House Edge, Probability, and Payouts.

If you catch yourself reading streaks into RTP, review The Gambler’s Fallacy Explained (With Simple Examples).

Variance/Volatility: What It Tells You About Swings, Bankroll, and Session Experience

Variance and Volatility: Practical Meanings

Variance describes how far your results tend to swing around the average over a set number of bets.

Volatility is the casino term for the same idea, most common in slots. High volatility means bigger swings. Low volatility means smaller swings.

RTP tells you the long-run average return. Variance tells you how rough the path can be on the way there.

Same RTP, Different Session Results

Two games can share the same RTP and still feel completely different in a session.

• One game pays small wins often. Your balance moves in short steps.
• Another game pays rarely, but hits large when it does. Your balance drops for long stretches, then jumps.

Over a short session, variance can dominate your experience. RTP shows up slowly.

Low, Medium, High Variance: What to Expect

• Low variance. Higher hit frequency. Smaller average win size. Longer playtime per bankroll. Fewer extreme upswings and downswings.
• Medium variance. Mixed hit rate and payout size. Moderate swings. Common in many mainstream slots and side bets with mid-range payouts.
• High variance. Lower hit frequency. Larger payouts when you hit. More bust-outs. Bigger spike potential. Shorter average survival time for a given bankroll.

Use RTP and Variance Together

RTP helps you compare long-run cost. Variance helps you match the game to your session goal and bankroll.

• If you want steadier sessions, prioritize lower variance even if RTP looks similar.
• If you accept frequent losing streaks for a shot at a big hit, high variance fits better.
• If you compare two games, pick higher RTP first, then use variance to choose the ride.

For odds-first comparisons, use house edge rankings in Which Casino Games Have the Best Odds? Ranked by House Edge.

Bankroll and Bet Sizing: The Simple Risk-of-Ruin View

Risk of ruin means the chance your bankroll hits zero before you reach a target win or a planned stopping point.

• Higher variance raises risk of ruin at the same bet size.
• Bigger bets raise risk of ruin in every game.
• More bankroll lowers risk of ruin, but never removes it.

Basic rule that works across games: if swings feel too large, cut your bet size. If you cannot cut your bet size, pick a lower-variance game.

Examples by Game Type

• Slots. Volatility varies by title. Low volatility slots pay more frequent small wins. High volatility slots rely on bonus features and rare big hits. Two slots can list similar RTP and still play nothing alike.
• Blackjack. Variance stays moderate with flat betting and basic strategy. It rises fast when you add side bets, raise stakes after losses, or chase losses. Rule changes also matter for house edge, so separate edge from variance when you compare tables.
• Roulette. Variance depends on the bet type. Even-money bets swing less than straight-up numbers. All roulette bets share the same house edge on a given wheel, but your session swings change with your bet selection.

More Essential Casino Terms (Quick Glossary A–Z Style)

Expected Value (EV)

EV is your average result per bet over the long run. Casinos build EV into the rules and paytable.

You can express EV with RTP or house edge. If RTP is 96%, EV is -4% of your total wagered. If house edge is 4%, EV is -4% of your total wagered.

EV does not predict your next session. It tells you the cost of volume.

Hit Frequency (Hit Rate)

Hit frequency is how often a game returns any win, even a small one. Slots often show it as a percent, or hide it behind vague labels.

High hit frequency can still lose fast. Many “wins” pay less than your bet, so your balance still drops.

Payout Percentage vs Payout Rate

Payout percentage usually means RTP. It measures expected return over a large sample of bets.

Payout rate often describes how a game pays, like how often it pays, how much it pays on average when it hits, and how much it concentrates value in bonus features.

Do not treat “pays often” as “high RTP.” They are different levers.

Paytable and Game Rules

The paytable and rules drive the math. Branding does not. Two games with the same theme can have different RTP, variance, and side bet costs.

In table games, small rule changes move the edge. Blackjack rules like dealer hits soft 17, surrender, and 3:2 vs 6:5 change your expected loss. In roulette, a single zero vs double zero changes the edge.

Learn to read the rules before you bet. Use this guide for a step-by-step approach, How to Read Casino Game Rules and Paytables.

Random Number Generator (RNG) vs Live Dealer Outcomes

RNG games use software to produce outcomes. Each spin or hand resolves from a random draw. Past results do not change the next draw.

Live dealer games use real cards and wheels. Outcomes still stay random, but the process differs. Card depletion matters within a shoe, and the shuffle resets it.

RNG and live can share the same rules but still differ in speed, limits, and side bet options. Speed changes your hourly cost because you place more bets.

Progressive Jackpot

A progressive jackpot grows as players wager. A slice of each qualifying bet adds to the jackpot.

Progressives usually trade steady return for top-heavy payouts. They often raise variance and can lower base-game value.

Contribution Rate

Contribution rate is the share of each bet that feeds the progressive. Example, a 1% contribution adds $0.01 per $1 wagered to the jackpot pool.

This money comes from somewhere. It can reduce the base-game RTP unless the published RTP already includes the average jackpot contribution and hit behavior.

Seed Value

Seed value is the starting jackpot amount. When someone wins, the jackpot resets to this number, then grows again.

A higher seed can make the jackpot feel worth chasing sooner, but you still need the odds and contribution math to judge value.

Bonus Rounds

Bonus rounds shift where the RTP lives. Many games place a large share of return inside rare features.

This raises variance. You can see long dry spells, then a single feature covers hours of losses.

Free Spins

Free spins add extra spins under special conditions. They often include altered reels, higher multipliers, or locked wilds.

They change your win distribution. They can increase variance even if the game keeps the same RTP.

Multipliers

Multipliers scale payouts when you hit. They often create bigger peaks and a wider spread of outcomes.

A multiplier does not guarantee better value. A game can add multipliers and lower hit rate or base pays to keep RTP flat.

Wagering Requirements (Playthrough)

Wagering requirements tell you how much you must bet before you can withdraw a bonus or its winnings. Example, a $100 bonus with 30x wagering requires $3,000 in bets.

This turns RTP into real expected cost. Approximate expected loss equals house edge times required wagering, adjusted for any restricted games and maximum bet rules.

High wagering can erase the bonus value even when the offer looks large.

Comps and Loyalty (Theo, Coin-In, Player Rating)

Casinos comp you based on theoretical loss, called theo. Theo equals your coin-in times the house edge.

Coin-in is your total amount wagered, not your buy-in and not your net loss. If you cycle $5,000 through a slot, your coin-in is $5,000 even if you end up down $200 or up $100.

Casinos rate you by average bet, decisions per hour, and time played. Faster games and higher edge games generate higher theo per hour, which can mean more comps, at a higher expected cost to you.

If you play on-property, follow table and slot etiquette to keep your session smooth, Casino Etiquette 101. If you want low-friction games with simple rules, start here, Best Casino Game for Beginners. For a math-first view, use this ranking, Which Casino Games Have the Best Odds?.

Quick Glossary A to Z

• Advantage play, legal strategies that reduce or flip the edge in specific conditions, like counting in blackjack or promo exploitation.
• Bankroll, the money you set aside for gambling. It controls bet sizing and bust-out risk.
• Bet per line, your wager on each payline in a slot. Total bet equals bet per line times number of lines, or the game’s equivalent.
• Coin-in, total amount wagered. It drives theo and many loyalty calculations.
• Dealer hits soft 17 (H17), a blackjack rule that increases the house edge versus dealer stands on soft 17 (S17).
• Edge sorting, identifying small card back differences to gain information. Casinos treat it as a serious vulnerability.
• Expected value (EV), your average outcome per bet over time, often negative in casino games.
• Free play, casino credit that must be wagered, often with limits on where it can be used.
• Game speed, bets per hour. It changes your expected hourly loss because it changes volume.
• Hand pay, a manual payout process for larger wins, depending on the casino and jurisdiction.
• Insurance, a blackjack side bet when the dealer shows an ace. It usually carries a high house edge.
• Jackpot, a large prize, fixed or progressive, typically low probability and high variance.
• Kelly criterion, a bankroll method used for positive EV betting, not typical casino play.
• Loss rebate, a promo that returns a portion of losses, often with wagering requirements attached.
• Max bet, the highest allowed wager. Bonuses often cap max bet, and breaking it can void winnings.
• Near miss, a result that looks close to a big win but has the same EV as any other losing spin.
• Odds (true odds), the real probability-based price of an outcome. Casino payouts often sit below true odds.
• Payline, a pattern that determines winning symbol combinations on a slot.
• Quads, four of a kind in poker-style games. Payout depends on the paytable.
• Return to player (RTP), expected long-run return as a percent. House edge equals 100% minus RTP.
• Side bet, an optional extra bet, usually higher edge and higher variance than the main game.
• Theo, theoretical loss used for comps, calculated from coin-in and house edge.
• Upcard, the dealer’s visible card in blackjack. It drives basic strategy decisions.
• Variance, how widely outcomes swing around EV. Higher variance means bigger streaks and bigger swings.
• Wagering requirement, the playthrough needed before you can withdraw bonus funds.
• Zero (0, 00), roulette pockets that create the house edge.

How to Use These Metrics Together to Choose Games (Practical Checklist)

Practical Checklist: Use the Metrics Together

• Step 1, start with RTP or house edge. Pick the best math first. Higher RTP and lower house edge wins. Use the same source and rules set when you compare games.
• Step 2, confirm the rules that change the edge. In table games, small rule changes swing EV. In slots, the paytable and features drive RTP and volatility.
• Step 3, check variance next. Low variance fits steady bankrolls and longer sessions. High variance fits big-hit chasing and short sessions.
• Step 4, match bet limits to your bankroll. Find minimum and maximum bets. Make sure you can afford normal swings without raising stakes under pressure.
• Step 5, sanity-check speed and hands per hour. Faster games burn bankroll faster. A small house edge still costs more when you play more rounds.
• Step 6, factor in bonuses and wagering requirements. If you play with a bonus, treat the playthrough as a real cost. Some games count less toward wagering, which changes your real EV.

Order of Operations: Math, Then Swings, Then Table Fit

• Compare RTP and house edge first. This sets your expected loss rate. Use it to rank options. For deeper breakdowns, see best odds by house edge and how casino odds work.
• Use variance to pick your risk level. Two games can share similar RTP but feel nothing alike. High variance means longer losing runs and bigger spikes.
• Use bet limits to make the plan playable. Your target bet size must sit well above the table minimum. If it does not, you will overbet or leave.

Match the Game to Your Goal

• Goal, longer playtime. Favor higher RTP, lower house edge, and lower variance. Keep bets small relative to bankroll. Slow the pace when you can.
• Goal, big-win chasing. Accept higher variance. Keep the house edge as low as you can within that category. Set a hard stop-loss because swings cut both ways.
• Goal, skill and control. Choose games where decisions matter and the house edge stays low with correct play. Stay consistent with strategy and avoid side bets with high edge.

When RTP Is Not Published: Signals and Safer Defaults

• Use category defaults. Favor games with known, stable math, like baccarat banker bet and standard blackjack with good rules. Treat novelty games as higher edge until proven otherwise.
• Look for transparency. Trusted providers publish RTP per game version. Regulated casinos list rule sets and paytables. Missing details usually means worse value.
• Check the paytable. In video poker, the paytable is the game. Avoid short-pay versions. In blackjack, confirm key rules like dealer hits or stands on soft 17, blackjack payout, surrender, and double options.
• Avoid high-edge add-ons. Side bets and bonus features often carry large house edges. If RTP is unclear, skip them.
• If you cannot verify, lower stakes. Your safest move is to reduce bet size and session length.

Quick Reference Table: What Each Metric Controls

Responsible Play Guardrails That Belong in Your “Strategy”

• Set a session budget. Use money you can lose. Separate it from bills and savings.
• Set a time limit. Faster games increase total wagers. Time controls total exposure.
• Set a stop-loss. Pick a number that ends the session. Do not chase losses with bigger bets.
• Lock in wins with a rule. If you hit a target, cash out a fixed share or end the session.
• Stay consistent. Rapid bet swings increase risk without improving EV.
• Keep etiquette tight. It reduces stress and mistakes at live tables. See casino etiquette basics.