House Edge

Lesson 6 of 12

The house edge is the mathematical advantage that allows casinos to make a long-term profit.

In European Roulette, the house edge is 2.70%.

This advantage exists because of the green zero (0). While most bets are paid as if there were only 36 numbers, the wheel actually contains 37 pockets.

Example:

A straight-up bet pays 35 to 1.

However, the true odds are 36 to 1 because there are 37 possible outcomes and only one winning number.

This small difference creates the casino's long-term advantage.

House Edge Comparison

• European Roulette: 2.70%
• American Roulette: 5.26%

Because American Roulette contains both a zero (0) and a double zero (00), the house advantage is almost twice as high.

Understanding the house edge is essential because it explains why no betting system can eliminate the casino's mathematical advantage.

Many players believe that betting systems can overcome the casino advantage.

Popular systems such as:

• Martingale
• Fibonacci
• D'Alembert
• Labouchere
• Paroli

change only how bets are managed.

They do not change:

• The wheel
• The probabilities
• The payouts
• The house edge

The mathematical expectation remains exactly the same.

Key Facts

• European Roulette house edge: 2.70%
• American Roulette house edge: 5.26%
• Created by the zero pocket
• Applies equally to all betting systems

Next Step

Continue with Expected Value to learn how mathematicians calculate the average result of a roulette wager over the long run.

Next Lesson: Expected Value →