Last updated: 10 August 2026
SimEngine is a deterministic battle-simulation engine, an editor for it, and a hosted service that runs simulation models you have published. You author the units, the skills, the element channels and the arena; the engine runs them and produces a playback.
It is a general-purpose simulator. Nothing in it reimplements, ships or depends on any other product's content or data, and no result it produces is a statement about anything outside the model you wrote.
SimEngine is an independent project. It is not affiliated with, endorsed by, or associated with the developers or publishers of any other product, game or company.
The local editor and engine run on your machine and are yours to use. There is no account behind them and no network call in authoring, validating, re-running or watching a playback.
The hosted service runs simulation models you have published to it, on our machines, and that is what the rest of this is about. Using it means accepting these terms; if you do not accept them, the local editor does not require them.
You keep every right you already had in what you author. Publishing a model grants us only what is needed to store it and to run it when a request asks for it — no right to publish, index, redistribute or display it, and no other use.
You are responsible for having the right to author what you author. Do not publish content you have no right to publish, or anything unlawful.
Model ids are immutable. Changing a model means publishing again and getting a new id; the old id goes on running exactly what it was running.
An account is a username and a password. There is no email address anywhere in this system, which is deliberate — and it has one consequence you should read twice. A recovery key is the only way back into an account whose password is lost, and it is shown to you once, when you generate it.
Lose the password and the recovery key and the account cannot be recovered. Not by asking, not by proving anything: there is nothing on file to prove it against. You can generate a new recovery key whenever you like, and each one replaces the last.
Capacity is finite and shared. The service enforces the engine's published limits — a duration bound, a request-size bound, a wall clock — and each limit's own enforcement, refusal or visible truncation, is published beside it. Beyond that:
Access may be limited or withdrawn where any of this happens, without notice.
You can delete a hosted model yourself, at any time, and doing so removes its stored bytes. We may also remove a model or suspend an account where we are required to, or where these terms are being ignored.
Takedown requests are handled by model id, because that is the only handle the service has — nothing is browsable, searchable or titled. If you believe a hosted model infringes your rights, send the id to hello@simengine.net and it will be dealt with.
The service is provided as is. It may be slow, unavailable, or withdrawn. No level of availability, response time or throughput is promised anywhere on this site, and none should be inferred from anything on it.
Determinism is a measured property, not an adjective. The intro states exactly what has been measured and what has not; nothing beyond that is promised, and no result is claimed for a platform other than the one you run on.
Running is metered in simkens and charged against a balance. A refused request is not charged. Purchased credit is consumed by runs made with your API key, and where a payment fails or is reversed the credit it would have bought is not granted.
Prices and the retail multiple are published and may change. A change applies to purchases made after it, and never retroactively to credit already bought.
To the fullest extent the law allows, liability for any loss arising from using — or being unable to use — this service is limited to the amount you paid for it in the period concerned. Nothing here excludes liability that cannot lawfully be excluded.
These terms, and any dispute arising out of or in connection with them, are governed by the law of England and Wales. The courts of England and Wales have exclusive jurisdiction, except where the law of the country you live in gives you the right to bring a claim in your own local courts.
These terms may change. The date at the top changes with them, and continuing to use the hosted service after a change means accepting the current version.