Designing a Well-Structured Keno Game: Game Engine, Randomness, and Payouts

2026-01-04•5 min read•Keno, Game Engine, Random Draw, Randomness, Payout Calculation, iGaming, Backend Design

Overview

Keno is a lottery-style casino game where players select numbers from a pool, and a random draw determines the winners. While the gameplay appears simple, designing a robust Keno system requires careful attention to fairness, randomness, and payout logic. This article breaks down key components of a well-structured Keno game.

Game Engine

The game engine is the core of a Keno system. It orchestrates player sessions, bets, draws, and payout calculations. A robust engine ensures consistency, prevents cheating, and allows high concurrency for multiple simultaneous players.

  • Session management: Track player selections, bet amounts, and game history.
  • Draw execution: Generate random numbers securely and fairly.
  • Payout calculation: Compute winnings based on the number of hits and configured paytables.
  • State persistence: Save results and player balances for audits and session recovery.

Random Draw

The random draw is the heart of Keno. A set number of winning numbers are drawn from a pool (commonly 1–80). The draw must be unpredictable, fair, and resistant to manipulation.

  • Secure RNG: Use cryptographically secure random number generators (CSPRNG) to prevent predictability.
  • Unique draws: Ensure no duplicates are drawn unless the rules explicitly allow it.
  • Server-side calculation: Avoid generating draws on the client to prevent tampering.

Randomness

Randomness ensures fairness and player trust. In Keno, it prevents players from predicting outcomes. True randomness is critical, especially in regulated gambling environments.

  • Entropy: Seed RNGs using high-entropy sources to make draws unpredictable.
  • Auditability: Log draws and RNG seeds securely to enable regulatory audits.
  • Statistical validation: Periodically test draws to ensure uniform distribution and fairness.

Payout Calculation

Payouts in Keno depend on the number of hits between the player's selection and the drawn numbers. Paytables define the multiplier for each number of hits and may vary based on selected numbers or bet amounts.

  • Hit-based payouts: Each combination of hits has a defined multiplier, e.g., 3 hits = 5x, 5 hits = 50x.
  • Dynamic paytables: Operators can adjust payouts based on risk management, popularity, or special events.
  • Server-side calculation: Ensures fairness and prevents client manipulation.
  • Audit trail: Store all bets, hits, and payouts to allow replay and compliance checks.

Design Principles

  • Separation of concerns: Keep game engine, API, and frontend logic distinct for maintainability.
  • Scalability: Stateless endpoints and persistent session storage support high concurrency.
  • Fairness & Security: All calculations, draws, and RNG must occur server-side with proper logging.
  • Player experience: Smooth animations, clear hit display, and immediate feedback improve engagement.

Summary

Designing a Keno game is not just about creating a number grid; it involves a secure and robust game engine, cryptographically secure draws, careful payout logic, and scalable architecture. By focusing on fairness, randomness, and clear separation of concerns, developers can create a professional, reliable, and engaging Keno experience suitable for modern iGaming platforms.