Some Module design questions from a Vassal noob

Hi there,

I am pretty new to Vassal and I am trying to determine if the Vassal engine can do what I need it to do before I invest the time in figuring out how it all works. Thanks in advance for taking the time to read and answer.

I am seeking to create a playtest module for my grand strategy ww2 game.

Q1: My counters are two sided. The placement of the counters on my map is open to all players to see, but the type of unit indicated by the counter needs to remain secret before combat. Will a Vassal version allow for players to freely inspect the underside of their counters without revealing them to their opponents?

Q2: Where can I find up to date tutorials on module design? I see there are some very old ones on Youtube.

Thanks again!


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You want the Mask trait for doing that.

Cheers. Thanks for the tip.

I think that you will find the 101 youtube series by Joel Toppen gets you going very well, even if though it is based on an earlier version of Vassal.

You will discover the new features as you go, from the drop down menus in the editor, in-built help
and the Reference Manual. This forum or the Discord server are good sources of support when you need it.


Ok, great! Thanks for the info.

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I’ve using the layer trait works better. Uncheck the always active box. Use your reverse side for the layer image. The layer can be used for multi-strength units, like in Anzio.

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Thanks for the tip. Quick question: why uncheck the “always active” box?

Layer is great for two-sided pieces, but his request centered on secrecy, which is why Mask was recommended as an alternative. Layer doesn’t involve ownership or privileged viewing, so “flipping” the piece (i.e. activating/deactivating the Layer) will change the graphical representation of the piece for all players, not only the owning player who wants to secretly have a look–you could only have that privileged look by pulling the pieces off to some private window first.

With Mask, you can restrict the ability to flip (or peek, which is a temporarily look without actually flipping) to specified player sides, which is why it’s better suited to the presented use case.


When the trait layer is active, it will cover all the images from traits above it in the list. (Vassal reads traits from bottom to top.) Thus you usually want the layer to be inactive so you don’t cover the image in the basic trait until you want to. Alternately, you could leave the basic image empty and put all the images you want in the layer trait. Then you would want it always active.

If as JoelCF25 suggests, secrecy being an issue, the mask trait would serve you better. Keep in mind though, it will give you only one alternate image.

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Thank you very much for this clarification!