House Edge & RTP — The Two Numbers That Decide Your Bankroll
What house edge and RTP actually mean, how operators advertise them, and why they only matter over the long run.
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- PK Casino Guide editorial
Two numbers explain almost everything
If you only ever learn two technical concepts about gambling, learn house edge and RTP. They explain why some games are worse than others, why ‘winning streaks’ are not permanent, and why the casino is — quite openly — guaranteed to make money across all its players.
House edge — what it really measures
House edge is the percentage of every wager that the casino expects to keep, on average, over a very large number of plays. It is not a prediction of what happens to you in a session — it is what happens across millions of bets by millions of players combined.
If a game has a 2% house edge, every ₨100 wagered returns, on average, ₨98 to players. The casino keeps the ₨2. Across the millions of bets the operator processes daily, that ₨2 per ₨100 is what builds the casino.
RTP — the same thing, flipped
Return to Player (RTP) is just the inverse of house edge, expressed from the player's perspective. If a slot has 96% RTP, it has a 4% house edge. They describe the same fact.
RTP is more common in slots and digital games; house edge is more common in table games. Same math, different angles:
- 96% RTP = 4% house edge
- 94% RTP = 6% house edge
- 99.5% RTP = 0.5% house edge (best-case blackjack with basic strategy)
House edge across common games
| Game / bet | House edge | RTP | Notes |
|---|---|---|---|
| Blackjack (basic strategy) | ~0.5% | ~99.5% | Lowest of any common game — if you play correctly |
| Baccarat (Banker) | ~1.06% | ~98.94% | Best bet at the table |
| Baccarat (Player) | ~1.24% | ~98.76% | Almost as good |
| Roulette (European) | 2.70% | 97.30% | Single zero only |
| Andar Bahar (main bet) | ~2.15% | ~97.85% | Avoid all side bets |
| Roulette (American) | 5.26% | 94.74% | Avoid — same payouts, double zero |
| Online slots (good) | 4–6% | 94–96% | Check before playing |
| Online slots (mobile / unlicensed) | 10–15%+ | 85–90% or worse | Almost guaranteed loss over time |
| Baccarat (Tie) | ~14.4% | ~85.6% | One of the worst common bets |
| Most casino side bets | 5–25% | 75–95% | Treat as entertainment cost only |
Why ‘long run’ is the catch
Here is the most-misunderstood part: house edge does not describe what happens in your session. It describes the average over an enormous number of bets.
In a 30-minute session of European roulette, you might walk away up 50× your stake. You might lose everything. The 2.70% edge only emerges as a reliable pattern across thousands of spins.
This works in the casino's favour, not yours. The casino processes millions of bets per day across all players, so the long run is the only time scale that matters to it. You only have your session — so for you, the actual risk is variance.
Variance — the part operators don't advertise
Variance describes how widely actual results swing around the expected average. High variance = bigger possible wins, bigger possible losses, fewer balanced sessions. Low variance = smaller swings, more predictable outcomes.
A slot can be advertised as ‘96% RTP’ while being high variance: weeks of small losses interrupted by rare large wins. The math still adds up to 96% over millions of spins — but your single bankroll could vanish during one of the long dry stretches.
What this means for you
- Avoid high-edge games. American roulette, Tie bets in baccarat, most slot side bets, and any slot with RTP under 94% are losses waiting to be realised.
- Avoid playing many hands per hour. The house edge applies per bet. Fast play burns through bankrolls faster, even on low-edge games.
- Match bankroll to variance. If you only have a small bankroll, pick low-variance games. Pursuing high-variance slots on a small bankroll almost always ends badly.
- Accept that you cannot beat the house edge by playing more. More play means more exposure to the edge, not less. The only sustainable strategy is to limit how much edge you give the casino.