House edge vs RTP vs variance — the three numbers that matter
RTP tells you the long-run cost, house edge tells you the same thing from the other side, and variance tells you what tonight will actually feel like.
Key takeaways
- House edge = 100% − RTP. They are the same fact stated twice.
- Variance measures how far individual results scatter around the average.
- High variance means long dry spells punctuated by large hits.
- Match variance to your bankroll, not to your optimism.
Three numbers describe any game of chance. Two of them are the same number wearing different clothes, and the third is the one that actually determines whether you have a good evening.
House edge is RTP inverted
If RTP is 90%, the house edge is 10%. That is it. A 10% edge means that on average the platform retains one tenth of everything wagered. Note that this is on turnover, not on deposits — if you deposit 100 USDT and wager it five times over as you win and re-stake, the expected cost is 10% of 500, not 10% of 100. This is why session length matters more than deposit size for expected loss.
Variance is the shape of the ride
Two games can share an identical 90% RTP and feel like completely different products. One pays 0.95x almost every round and never does anything exciting. The other pays nothing 97 times and then pays 300x. Same expected return, radically different experience — and radically different bankroll requirements.
| Profile | Typical surface | What it feels like |
|---|---|---|
| Low variance | Coinflip, cheap boxes | Frequent small results, slow drift |
| Medium variance | Wheel, Plinko middle rows | Regular wins, occasional runs |
| High variance | Grand-prize boxes, Crash at high targets | Long droughts, rare large hits |
Why high variance drains bankrolls faster
Not because it is less fair, but because the drought between hits can easily exceed your funds. If a prize hits once in 400 openings and you can afford 60, the mathematically expected outcome and the practically likely outcome diverge completely: you will most probably never see it, even though the odds are exactly as published. Bankroll must be sized against the gap between wins, not against the average.
Putting the three together
- 1Read RTP to know the long-run cost of playing.
- 2Convert it to house edge and multiply by expected turnover to get expected spend.
- 3Read variance to decide how many rounds you need to survive.
- 4Size your session so the third number, not hope, sets your limit.
Do that and you stop being surprised by outcomes that were always inside the distribution. Chance stays chance — you just stop mistaking it for a malfunction.
Compare variance profiles across the whole games lobby.
Browse the games