Deterministic game engine

A game engine architecture where identical inputs always produce bit-for-bit identical outputs across different machines.

Deterministic engines (like those powering Age of Empires or StarCraft) eliminate state synchronization issues by simulating game logic through fixed-step updates and integer math. By ensuring that the same sequence of player inputs results in the exact same game state on every client, developers reduce network traffic to mere input packets rather than massive object snapshots. This approach enables massive unit counts (1,000+ entities) and seamless instant-replay systems by relying on the mathematical certainty of the simulation's execution path.

https://gafferongames.com/post/deterministic_networking/