AP Glossary
WhatIsBaseGameReturn?
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.
Why It Matters
Why this matters for advantage play
When you decompose a slot's RTP into base + bonus + progressive, the base game return is the part you cannot influence as an advantage player. Everything else is what you exploit. The lower the base game return, the more bonus or progressive value you need to flip the play to +EV.
Cross-Reference
Related terms
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.
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% indicates a +EV situation.
EV (Expected Value)
The mathematical average outcome of a bet calculated over infinite repetitions. Positive EV (+EV) means the play is profitable long-term; negative EV (-EV) means the house has the edge. AP players only take +EV plays.
Threshold
The specific meter value or counter level at which a machine transitions from -EV to +EV. Run the Slots calculates trigger thresholds for every supported machine based on base game return, meter rates, and bonus values.
Frequently Asked
Common questions about base game return
Subtract the expected bonus contribution and any progressive contributions from the certified total RTP. Bonus contribution can be approximated from observed trigger rates and average bonus payout; progressive contribution comes from the meter rate.
For pure entertainment players, yes. For advantage play it's nuanced — high base return often means smaller bonus/progressive contribution, which can mean less leftover value to harvest from a stranded meter.
Link series titles like Lightning Link and Dragon Link typically run 85–88% base game return, with the remaining payback funneled into the hold-and-spin bonus and minor progressives.
Ready to put base game return into practice?
Get access to 150+ machine-specific advantage play guides with exact trigger points, walk-away rules, and floor-walk routes.
Get Access