Roulette Glossary

Last updated: 2025-12-26

Roulette (French: roulette, “little wheel”) is one of the most well-known table games among casino games. The game determines the winning number and related properties (such as color and even/odd) using the wheel and ball. Roulette uses internationally established terminology, and knowing the terms helps understand table markings, bet types, and multipliers.

This guide compiles roulette’s key terms and bet forms neutrally and rule-based. Content focuses on terminology, game mechanics, and probabilities, not campaigns or marketing.

Basic Roulette Concepts

Table and Wheel

Roulette has two key parts: the betting table (layout), where bets are placed, and the wheel, where the ball lands in one of the numbered pockets. European roulette typically has numbers 0–36. Some variants (for example, American roulette) also have 00, which changes the game’s mathematical edge.

Croupier

Croupier (game supervisor) is responsible for the practical flow of the game, such as closing bets, spinning the ball, and paying winning bets and collecting losing ones. In live environments, the croupier’s announcements and hand signals are part of the game’s standardized operation.

House Edge and Probabilities

Roulette’s return to player (RTP) and house edge are determined primarily based on the number of zeros. A single bet’s “hit probability” depends on how many numbers or properties the bet covers. Multipliers are generally fixed and based on the number of numbers covered by the bet form.

Numbers and Colors

Big Numbers and Small Numbers

• Big Numbers means numbers 19–36
• Small Numbers means numbers 1–18

These are so-called outside bets, where you bet on a broad set of numbers. In European roulette, zero does not belong to either group, which affects the result when the ball lands on zero.

Rouge ou Noir

Rouge ou Noir means betting on red or black. On the table, numbers are marked red or black (zero is green). Although red and black have the same count (1–36), zero does not belong to either, which is a key reason why the bet is not mathematically “even” over the long term.

Pair ou Impair

Pair ou Impair means even or odd. The bet targets numbers 1–36 based on their even/odd status. Zero is neither even nor odd, so it is treated as a separate result according to game rules.

Inside Bets

Inside bets (inside bets) refer to bets placed on individual numbers or small number groups within roulette’s number area. They are generally higher variance bets: hits are less frequent, but multipliers are larger.

Straight and Split

• Straight is a bet on one number. Typical win multiplier is 35:1.
• Split is a bet on two adjacent numbers. Typical win multiplier is 17:1.

A straight bet is placed directly on one number. A split bet is placed on the border between two numbers, covering both numbers.

Street and Corner

• Street covers three numbers from the same horizontal row. Typical win multiplier is 11:1.
• Corner covers four related numbers (corner bet). Typical win multiplier is 8:1.

Street and Corner are common ways to expand coverage without moving to outside bets.

Trio and Basket

• Trio means a bet on three numbers, typically a combination of 0–1–2 or 0–2–3 (depending on table structure).
• Basket means a bet on the first four numbers 0–3.

Zero-related inside bets are their own special group in roulette, as zero is positioned on the table separately from the rest of the number area.

Outside Bets

Outside bets (outside bets) are placed outside the number area and cover a larger number of numbers. Multipliers are smaller than in inside bets, but hits are expected to occur more frequently.

Dozen

In Dozen bets, numbers are divided into three dozens:

• Première Douzaine numbers 1–12
• Moyenne Douzaine numbers 13–24
• Dernière Douzaine numbers 25–36

Typical win multiplier for a dozen bet is 2:1. Zero does not belong to dozens.

Column Bet

A Column bet (column bet) targets one of three vertical columns, each covering 12 numbers. As with dozen bets, typical win multiplier is 2:1 and zero remains outside columns.

Snake Bet

Snake Bet is a non-standard bet form where the bet is placed following a “snake-like” pattern on the following numbers: 1, 5, 9, 12, 14, 16, 19, 23, 27, 30, 32, and 34. Not all gaming platforms support this bet, and its implementation may vary (for example, as one combination bet or multiple split bets).

Win Multipliers and Bet Coverage

Roulette multipliers are tied to how many numbers the bet covers. Below is a summary of commonly used multipliers (in European roulette):

Strategies and Systems

In connection with roulette, betting systems and strategies are often discussed, such as Martingale and D’Alembert. These do not change roulette’s basic mathematics (such as house edge), but they describe ways to vary bet size based on results. Strategies have practical limitations, such as table minimum and maximum bets and limited bankroll.

For more information on roulette systems, see: strategies. Background on safety and game approach can also be found here: four-step strategy for safe online roulette and roulette game formats and terms: mini roulette.

Why Roulette Glossary is Useful

Roulette terms relate directly to how bets are placed, what they cover, and how wins are calculated. Mastering the glossary especially helps with the following:

• distinguishing bet forms from each other based on table markings
• understanding multipliers and coverage without interpretation
• grasping differences between game formats (for example, European and American roulette)

Related Reading

FAQ

What is the difference between inside bets and outside bets in roulette

Inside bets are placed inside the number area and typically cover 1–6 numbers, so multipliers are larger and hits less frequent. Outside bets are placed outside the number area and cover broad categories, such as red or black, even or odd, or dozens.

Why is zero an important number in roulette from a probability perspective

In European roulette, zero does not belong to, for example, red or black, nor to even or odd numbers. This adds one additional option to the outcome space, which appears as house edge and especially affects outside bets.

Are roulette win multipliers always the same

Basic multipliers are established in most roulette versions (for example, straight 35:1). Exceptions may occur in certain game formats or special rules, so multipliers and rules should always be checked in the specific game’s instructions.

What do Martingale and D’Alembert mean in roulette

They are betting systems where bet size is changed based on previous rounds’ results. Systems do not change individual round probabilities, and their effectiveness in practice depends on, among other things, table limits and bankroll size.