A-Z Reference

Advantage Play Glossary

Every term you need to know as a slot machine advantage player. 37 definitions with clear explanations and links to in-depth guides.

P

R

A

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 page Accumulator 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.; View detailed page

B

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 page Bankroll 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.; View detailed page
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.; View detailed page
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.; View detailed page

C

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 page MHB Progressives Explained
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 page Coin-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 page How to Read Counters

E

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 page How to Calculate EV

F

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.; View detailed page
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 page Casino 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 page Free Games Accumulator Slots

G

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.; View detailed page

H

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 page Hold 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 page Dragon 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.; View detailed page

L

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 page Linked 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 page Lightning Link Strategy

M

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 page MHB 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.; View detailed page
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 page MHB Strategy Guide

N

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.; View detailed page

P

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 page Persistent 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 page Progressive Jackpot Guide

R

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.; View detailed page
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 page Slot Machine RTP List

S

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 page Session 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 page Bankroll 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.; View detailed page

T

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.; View detailed page
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.; View detailed page

V

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 page Variance Guide
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 page Volatility 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.; View detailed page

W

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 page Walk-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.; View detailed page

Back to top

Ready to go pro?

Get access to 204+ machine-specific advantage play guides with exact trigger points and strategies.

Get Access

Related Articles

Ready to go pro?