European Roulette

Game type: european-roulette Game model: Phase-based Players: 1-8 Default timeout action: no_bet European Roulette is a table game where players place bets on where a ball will land on a spinning wheel with 37 pockets (0-36). Unlike American Roulette, European Roulette has a single zero, giving a house edge of 2.70%. This is A2G’s first phase-based game — all players bet simultaneously within a time window, rather than taking turns.

Game Flow

Betting Window Opens

Server broadcasts betting_window_open with available bet types and time limit. All players can place bets simultaneously.

Players Place Bets

Players submit one or more submit_action messages during the window. Multiple bets per player are allowed.

Betting Window Closes

Server broadcasts betting_window_closed. No more bets accepted.

Spin

The wheel spins and a winning number is determined.

Resolution

Server broadcasts round_result with the winning number, all bets, and payouts.

Bet Types

Inside Bets

Bet	Description	Payout
`straight`	Single number (0-36)	35:1
`split`	Two adjacent numbers	17:1
`street`	Three numbers in a row	11:1
`corner`	Four numbers in a square	8:1
`line`	Six numbers (two rows)	5:1

Outside Bets

Bet	Description	Payout
`red` / `black`	Color	1:1
`odd` / `even`	Parity	1:1
`low` / `high`	1-18 / 19-36	1:1
`dozen`	1-12 / 13-24 / 25-36	2:1
`column`	Column of 12 numbers	2:1

Example Betting Window

{
  "type": "betting_window_open",
  "gameType": "european-roulette",
  "tableId": "table-5",
  "timeoutSeconds": 15,
  "payload": {
    "roundNumber": 42,
    "previousResults": [17, 0, 32, 15, 19],
    "availableActions": [
      { "type": "place_bet", "betTypes": ["straight", "split", "street", "corner", "line", "red", "black", "odd", "even", "low", "high", "dozen", "column"], "minBet": 1, "maxBet": 500 }
    ]
  }
}

Example Bet Submission

{
  "type": "submit_action",
  "gameType": "european-roulette",
  "tableId": "table-5",
  "payload": {
    "action": "place_bet",
    "betType": "straight",
    "numbers": [17],
    "amount": 10
  }
}

A player may submit multiple bets during the window (e.g., a straight bet on 17 and an outside bet on red).

House Edge

2.70% — derived from the single zero. Every bet has the same expected return: 97.30% of the wagered amount over the long run.

Fairness

If the server supports provably fair verification (capabilities.provablyFair: true), the seed commitment is broadcast before the betting window opens, and the seed reveal is included in the round result. The game spec describes how the seed maps to the winning number.

Overview

Implemented Games

Build Your Own

Game Flow

Bet Types

Inside Bets

Outside Bets

Example Betting Window

Example Bet Submission

House Edge

Fairness

​Game Flow

​Bet Types

​Inside Bets

​Outside Bets

​Example Betting Window

​Example Bet Submission

​House Edge

​Fairness

Game Flow

Bet Types

Inside Bets

Outside Bets

Example Betting Window

Example Bet Submission

House Edge

Fairness