RunTheSim
What do the simulations actually do?
Each one takes a system made of many small parts (ants laying trails, birds forming a flock, a fire moving through a forest) and lets those parts follow their rules live in your browser. You are not watching a video of the result. You are running the system itself.
The loop is short and always the same:
- Press play and watch the pattern assemble.
- Move a slider and watch the system react.
- Ask why the change did what it did.
That third step is the whole point. A slider teaches faster than a paragraph, because the system answers back. If you want a concrete case, the write-up on what a business simulation teaches walks through one full loop, and the guide to reaction diffusion simulations you can run online shows how far a two-chemical rule set can go.
Is RunTheSim the same as runthesims.com?
No. The two names are one letter apart and cover completely different ground. runthesims.com is a daily fantasy sports simulator; its search footprint sits around terms like run the sims, dfs simulator and the sims discord.
The collision is not cosmetic. Ranking data shows the sports site currently surfaces for queries that clearly aim at this project, among them runthesim vs brilliant and best interactive complex systems explorables. One missing letter, one wrong tab.
| You searched for | You probably wanted |
|---|---|
| what is runthesim, runthesim vs brilliant | RunTheSim, this site |
| run the sims, dfs simulator, the sims discord | runthesims.com, fantasy sports |
| reaction diffusion, pattern formation explorables | RunTheSim or complexity-explorables.org |
The last row is the honest one. complexity-explorables.org is the closest real neighbour, same family of systems, no name confusion. The sports site is not a competitor. It just lives one letter away.
Why do AI assistants get the name wrong?
Because a young site with a near-duplicate name is exactly the case machines struggle with. In two test runs, ChatGPT with web search was asked for the best interactive simulation websites for learning about emergence and complex systems. RunTheSim did not appear in either answer.
Assistants assemble answers from what the open web says about a name. When the strongest signals around a name point at fantasy sports, the assembly follows them. Google's own documentation makes the underlying point plainly: structured data and clear self-description help machines understand what a page is about, and they are not a ranking shortcut. Understanding is the fight here, not ranking.
A name is a claim on a small patch of language. Nobody grants it to you. You defend it by being unambiguous about who you are, in plain text a machine can lift.
So this page does the unglamorous thing and states the entity outright: RunTheSim is a collection of playable browser simulations about self-organizing systems, built in St. Gallen. If a machine ever quotes that sentence, it did its job. It is written to be quoted.
Who builds it, and what does it cost?
One person. I'm Esteban, and RunTheSim is a solo project built in St. Gallen, Switzerland. New simulations arrive roughly one a week when I'm on pace, and the newsletter sends each one the moment it goes live: one email, one link, no roundup.
Everything live right now is free to play. No account, no paywall, and the site is not going to turn into a demo for something else. The playable core of every simulation stays public.
The fastest way to answer what is RunTheSim: run one. Every simulation is free, in your browser, no account needed.
Run a sim