Requirements for vassal and how to install a server?

What are the requirements for a vassal client(?)/user/terminal? I haven’t found this in the documentation.

What are the requirements for a server?

Are there any instructions for installing a server? I know little about vassal but have been asked about installing a private server and a couple of clients to run a local game. Is this even possible? Are there binaries? I really don’t want to have to compile code.

The minimum requirements for the Vassal client are in the release notes for each version.

The only hard requirement is that your system be able to run Java 11 or later.

To run a server, you’d need a system able to run Java 11.

No. It’s not a thing we encourage, for two reasons:

  • Wanting to run a private server in nearly all cases stems from a misunderstanding about how the public server works. I can remember maybe three cases in the past where someone actually needed a private server.
  • The yield we’d get from our effort supporting private servers is much lower than other ways we could spend the same effort.

It is possible, but why do they want that? What’s the obstacle to using the public server? Please explain.

You can run the game server from lib/Vengine.jar, which is part of each Vassal release. There is nothing separate to compile. The entry point is and you can find out about the options by reading the code for that class.

Wanting to run a private server in nearly all cases stems from a misunderstanding about how the public server works

What is this misunderstanding?

The place they’re going to play is in the country with not very good access to the internet.

In that case, a peer-to-peer connection would probably make the most sense. No reason to bother with a private server.

It’s not one single misunderstanding across all cases, but one misunderstanding in each case.

I’d try P2P first in that case.

Oh, Vassal can do this? I didn’t know.

I looked through and I didn’t see CPU or memory requirements, just OS. Is that enough? Just reasonably current Windows, Linux, or MacOS? Do some games require more memory?

Any machine from the last 15 years or so will have enough RAM to run Vassal, but the actual minimum you’ll need depends what module you’re using, so we can’t state it generally.

Java requires setting a “maximum heap size” for programs it runs, which is the maximum amount of memory the program is allowed to use. We use 512MB as a default in current versions of Vassal, but there are many modules which would run fine with less. There are some modules where you’ll need to set that higher—some to 1024MB, and a handful to 2048MB.

Thanks. How do I find the heap size needed for a module? The module is not on your website, apparently because it’s too big. I can’t seem to get a definitive indication of the size requirement. The module is World in Flames and these guys play the original board game. In one of their saved games that I’ve seen, they list a heap size of 4GB, (4096MB). Would it really need that much? Does the heap have to be in RAM?

Trial and error. If we had a way of automatically determining what an appropriate max heap was for a module, we wouldn’t confront the user with having to set it.

How large is it?

We’ve increased the size limit for modules we host many times over the years; this module may now be under the size limit, and if so, it would be good to let the maintainers know that.

It’s possible. The only way to know is to try.

Yes. It would be totally unusable if the heap is in swap.

Peer-to-Peer setup is on page 16 of the User’s Guide.

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Ah, OK, so the clients will have to have a decent amount of memory. More than the minimum base system and heap size.