A–Z reference
Advantage Play Glossary
Every term you need to know as a slot machine advantage player. 51 definitions with clear explanations and links to in-depth guides.
- A Play (“It’s a Play”)
- A machine whose number or condition clears the play threshold for its game — the number on it is right, so sitting down now carries an edge. Advantage players use it as a plain yes or no: it’s a play, or it isn’t. The phrase describes the machine at this moment, not the game in general.
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- Accumulator
- A slot machine that collects or banks a resource (coins, orbs, counters) over time toward a bonus trigger. Previous players' progress carries over, creating advantage play opportunities when the accumulated value is high enough.
- View detailed pageAccumulator Slots Guide
- Advantage Play (AP)
- The practice of using math, observation, and legal strategies to identify and play slot machines with a positive expected value. AP players only play when the numbers are in their favor.
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- Bankroll
- The total money a player has allocated specifically for advantage play sessions. Proper bankroll management ensures you can survive the natural variance of player-favorable play without going broke.
- View detailed pageBankroll Management Guide
- Banked Bonus
- A bonus feature that saves progress between players. When a previous player leaves a machine with a partially filled bonus counter, the next player inherits that progress — the core mechanic behind most accumulator advantage plays.
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- Base Game
- The regular slot game excluding progressive jackpots and bonus features. The base game return is typically 85-92% for modern slots, with the remaining return coming from bonuses and progressives.
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- Base Game Return
- The expected payback percentage of the slot's regular spins, excluding progressive contributions and bonus features. Knowing this helps calculate total RTP when adding progressive and bonus value.
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- Carded Play
- Playing with a players club card inserted, so the casino records your coin-in and returns part of it as points, comps and offers. Uncarded play earns nothing and is logged against the machine rather than against you. The choice is yours on every sit-down, and it can differ by property.
- View detailed pageHow Players Clubs and Comps Work
- Ceiling
- The maximum value a must-hit-by progressive can reach before it is forced to pay out. The closer a progressive gets to its ceiling, the higher the expected value of playing that machine.
- View detailed pageMHB Progressives Explained
- Class II
- A regulatory category defined by the Indian Gaming Regulatory Act of 1988: bingo and games similar to bingo, including electronic aids to bingo, plus certain non-banked card games. A Class II slot-style cabinet is a bingo game wearing slot artwork — the outcome is drawn from a bingo game shared with other connected players, and the spinning reels are a way of displaying a result that has already been decided. Class II gaming is regulated by the tribe with National Indian Gaming Commission oversight and does not require a tribal-state compact.
- View detailed pageClass II vs Class III
- Class III
- The Indian Gaming Regulatory Act's catch-all category: all gaming that is neither Class I (traditional and social tribal games) nor Class II. It covers conventional house-banked slot machines, table games, and most of what a commercial casino floor looks like. On tribal land, Class III gaming requires a tribal-state compact, and machines operate under that compact with National Indian Gaming Commission involvement.
- View detailed pageClass II vs Class III
- Coin-In
- The total amount of money wagered on a machine, not the same as money lost. A player who bets $1,000 in coin-in may only lose $50 if the machine returns 95%. Used to calculate counter rates and track session costs.
- View detailed pageCoin-In Explained
- Counter
- A visible or hidden tracker on a slot machine that accumulates toward triggering a feature. Counters may display as collected items, filling displays, or numerical values. When a counter is elevated, the machine may be in a player-favorable state.
- View detailed pageHow to Read Counters
- EV (Expected Value)
- The mathematical average outcome of a bet calculated over infinite repetitions. Positive expected value means the play is profitable long-term; negative expected value means the house has the edge. AP players only take plays where the math is in their favor.
- View detailed pageHow to Calculate EV
- Floor
- The starting or reset value of a progressive jackpot — the lowest point it returns to after a jackpot hit. The distance between the floor and the current counter value indicates how much has been contributed by players since the last hit.
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- Floor Walk
- Scouting the casino floor for machines in player-favorable states without playing. Experienced AP players develop efficient walk routes through a casino, checking counters on known advantage play machines.
- View detailed pageCasino Floor Strategy
- Free Games
- Bonus rounds with free spins accumulated by previous play. On some machines, free games are banked and carry over between players, making them a type of accumulator advantage play.
- View detailed pageFree Games Accumulator Slots
- Free Play
- Promotional credit loaded to your players account — from a mailer, a kiosk offer, a tier benefit or a host. It plays through a machine like cash but is not cash: the credit is consumed by the wager, and only what those wagers win becomes money you can take away. Offers carry expiry dates and often restrict which machines or denominations qualify.
- View detailed pageWhat Free Play Is Worth
- Grind
- The process of playing through player-favorable situations repeatedly over many sessions. AP is often a grind — small edges played consistently add up to meaningful profit, but individual sessions can be losing ones.
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- Handpay
- A payout the machine cannot settle itself, completed by casino staff instead. It is triggered either by a jackpot at or over the federal reporting threshold, which requires tax paperwork before you are paid, or by a win larger than the cabinet is configured to dispense. The game locks, a tower light or tone calls an attendant, and play stops until the payout is done.
- View detailed pageJackpot Hand Pay Guide
- Hit Frequency
- How often a spin returns any win at all, expressed as a share of spins. It says nothing about the size of those wins — a game can pay on a large fraction of spins and still return less than one that pays rarely. Hit frequency and payback are separate dials, set independently by the game's designer.
- View detailed pageHit Frequency Explained
- Hold
- The percentage of coin-in that the casino keeps. A machine with 8% hold returns 92% to players (92% RTP). Hold is the inverse of RTP.
- View detailed pageHold Percentage Guide
- Hold & Spin
- A bonus feature common in link-style games where locked symbols remain on screen while remaining positions spin for a set number of respins. Popular in games like Lightning Link, Dragon Link, and Buffalo Link.
- View detailed pageDragon Link Strategy
- House Edge
- The casino's built-in mathematical advantage on a game, expressed as a percentage. On a slot with 92% RTP, the house edge is 8%. Advantage play temporarily reverses this edge on specific machines in specific conditions.
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- Linked Progressive
- A progressive jackpot fed by multiple machines, causing faster jackpot growth than standalone progressives. Linked progressives across a bank of machines or an entire casino floor reach player-favorable thresholds more quickly.
- View detailed pageLinked Progressive Guide
- Link Game
- Slot machines featuring hold-and-spin bonus mechanics, typically with progressive jackpots. Examples include Lightning Link, Dragon Link, Buffalo Link, and Mighty Cash. Many link games offer advantage play opportunities through their progressive structures.
- View detailed pageLightning Link Strategy
- Loose / Tight
- Folk vocabulary for how much a machine gives back: a loose machine is said to pay generously, a tight one to grind. The underlying variable is real — the same title ships in several certified payback configurations and the operator chooses which to deploy — but in most US jurisdictions the configured return of an individual machine is not disclosed to players, and it cannot be read off the cabinet.
- View detailed pageWhat “Loose” Actually Means
- MHB (Must-Hit-By)
- A progressive jackpot forced to trigger before reaching a specified ceiling value. MHB progressives are the most mathematically analyzable form of advantage play because the ceiling creates a known upper bound for expected cost calculations.
- View detailed pageMHB Strategy Guide
- Meter Rate
- How fast a progressive jackpot climbs per dollar wagered — players call it the counter rate — expressed as cents per dollar of coin-in. A counter rate of $0.50 per $100 coin-in means the progressive grows by half a cent per dollar bet. Lower rates mean slower growth and higher cost to reach breakeven.
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- Midpoint Method
- A calculation technique for MHB progressives that estimates the breakeven point by finding the statistical midpoint between the current counter value and the ceiling. Assumes uniform trigger distribution — in practice, some games may be biased toward triggering near the ceiling.
- View detailed pageMHB Strategy Guide
- Near Miss
- A losing outcome displayed so that it looks close to a win — two jackpot symbols landing while the third stops just off the payline. The result was chosen before the reels finished moving, so nothing was nearly anything; the closeness lives in the presentation, not in the outcome.
- View detailed pageThe Near Miss Myth
- Negative EV (-EV)
- A situation where the expected mathematical outcome is a net loss. Most slot machines are -EV most of the time. Advantage players avoid -EV plays entirely — the discipline to walk away from -EV is what separates AP from gambling.
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- Par Sheet
- The manufacturer's maths document for a slot: reel strips, symbol weights, hit frequency, the pay table and the theoretical payback for each certified configuration. It is written for the regulator, the independent test lab and the operator. It is not published to players, and casinos are generally under no obligation to show one.
- View detailed pagePar Sheet Guide
- Persistent State
- A game feature that carries over between player sessions, such as collected wilds, counter values, or bonus progress. Persistent state mechanics are what make advantage play on slots possible — without them, every spin would be independent and always -EV.
- View detailed pagePersistent State Slots Guide
- Progressive Jackpot
- A jackpot that increases with each bet placed, funded by a small percentage of each wager. Progressives can be standalone (single machine) or linked (multiple machines). When a progressive grows high enough above its reset value, the added value can push the total RTP above 100%.
- View detailed pageProgressive Jackpot Guide
- Reel Strip
- The ordered list of symbols on a single reel, as defined in the game's maths. On a video slot the strip is a table in software rather than a printed band, and it is usually far longer than the few positions visible on screen. Its length and composition set how often each symbol can come up.
- View detailed pageReel Strips and Symbol Weighting
- Reset Value
- The value a progressive jackpot returns to after being won. Also called the floor or seed value. The difference between the current counter and the reset value represents the player-funded excess that contributes to advantage play opportunities.
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- RNG (Random Number Generator)
- The certified algorithm that selects each spin's outcome. On a regulated slot it runs continuously, and the instant you press the button decides which value is taken — so the result is fixed before the reels have finished spinning. Each outcome is drawn independently, which means nothing about the previous spin changes the next one.
- View detailed pageRandom Outcomes and Machine Fairness
- RTP (Return to Player)
- The theoretical percentage of wagered money returned to players over time. A 95% RTP means $95 returned per $100 wagered on average. RTP above 100% means the math is in your favor.
- View detailed pageSlot Machine RTP List
- Session
- A single play period on one machine. AP sessions are typically short — play only while the machine is in your favor, then leave. Long sessions grinding through house-favored territory is gambling, not advantage play.
- View detailed pageSession Strategy Guide
- Session Bankroll
- The amount allocated for a single playing session, separate from total bankroll. Session bankroll limits protect the overall bankroll from a single bad variance run.
- View detailed pageBankroll Management Guide
- Standalone Progressive
- A progressive jackpot fed only by the individual machine, as opposed to a linked progressive shared across multiple machines. Standalone progressives grow more slowly but the counter value is entirely attributable to play on that specific machine.
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- Threshold
- The specific counter value at which a machine transitions from house-favored to player-favorable. Run the Slots calculates trigger thresholds for every supported machine based on base game return, counter rates, and bonus values.
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- TITO (Ticket-In, Ticket-Out)
- The ticket system that replaced coin hoppers on most casino floors. Cashing out prints a barcoded ticket carrying your remaining credit, which you feed into another machine or redeem at a kiosk or the cage. Tickets carry an expiry date set by the operator within state rules.
- View detailed pageTITO Guide
- Trigger
- The specific condition that activates a bonus feature or progressive payout. In AP context, the trigger point is the threshold where playing the machine becomes mathematically profitable.
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- Variance
- The natural fluctuation of actual results around the expected value. High variance means bigger swings between wins and losses. Even player-favorable plays can produce losing sessions due to variance — bankroll management accounts for this.
- View detailed pageVariance Guide
- Virtual Reel
- A mapping layer between the generator's output and the reel positions a player sees. The game draws from a virtual list that can hold many more stops than the visible reel, then maps the result onto a displayed position. Several virtual stops can point at the same visible symbol, so symbols that look equally common are not.
- View detailed pagePhysical vs Virtual Reels
- Volatility
- How much results vary from the expected return in the short term. High volatility slots have infrequent but large payouts; low volatility slots pay smaller amounts more often. For AP, higher volatility means you need a larger bankroll to survive the swings.
- View detailed pageVolatility Guide
- Vulture / Vulturing
- The practice of finding and playing machines left in player-favorable states by previous players who didn't realize the value they'd built up. The term comes from the player 'swooping in' to collect value that others left behind.
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- Walk / Walk Away
- The discipline of leaving a machine or a casino when conditions are not favorable. Walking away from -EV situations — even when you're 'due' for a win — is the single most important habit in advantage play.
- View detailed pageWalk-Away Strategy
- WAP (Wide Area Progressive)
- A progressive jackpot linked across multiple casinos, such as Megabucks. WAPs grow extremely fast due to high volume but are rarely viable for AP because the base game return is very low and the trigger probability per spin is tiny.
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