Screeps: World
An MMO strategy sandbox where players program colonies with real JavaScript. Scripts run continuously in a huge persistent online world, automating harvesting, construction, logistics, trading, expansion and warfare even while the player is offline.
Why it’s a sandbox MMO
Screeps is built around player-authored automation rather than a conventional class or quest path. Colonies gather resources, build infrastructure, manufacture units, trade and compete for territory in a persistent shared world.
What makes it different
You do not directly control units moment to moment: you write the JavaScript AI that controls them. Your code keeps operating while you are offline, making programming skill itself the core progression system.
Sandbox systems
What makes Screeps a sandbox
Screeps shifts the usual MMO control model from character inputs to player-written automation. Instead of manually directing every worker or combat unit, players write JavaScript that decides how their colony gathers resources, builds structures, moves through the world and responds to other players.
That changes what progression means. The persistent world rewards planning, debugging and optimization as much as conventional character advancement. A successful colony is an expression of its owner's code and logistics strategy, and scripts continue operating while the player is offline.
Economy and territory
Resources are the foundation of expansion: colonies need harvesting and logistics before they can sustain more infrastructure and military activity. Because colonies occupy and contest rooms in a shared world, expansion can turn an economic problem into a territorial one. This creates a direct connection between gathering, production, trade and PvP.
Who the design is for
Screeps is an unusual fit for players who enjoy sandbox MMOs but also want programming itself to be part of the game. It is less about building a character around a class and more about building a functioning organization of automated units.
Useful comparisons
Its closest conceptual comparisons are other persistent-world games with player economies, automation or territorial competition. The key difference is that the player's code is the primary tool used to interact with those systems.