All real-time multiplayer games—from shooters to MOBAs—depend on one core mechanism:
the game loop, also known as the simulation loop.

The game loop is the server’s “heartbeat.”
It controls how often:

• Player inputs are processed
• The world updates
• Physics and collisions resolve
• Timers and cooldowns advance
• NPCs and AI behave
• State is broadcast to players

Understanding the game loop is essential for building fair, predictable, real-time gameplay.

1. What Is a Game Loop?

A game loop is a repeating cycle that advances the simulation one step at a time.