Are the any anti-cheat measures in VASSAL?

Since the module is open to anyone, is there any check to make sure the module hasn’t been tampered?

I haven’t tried online, but I created a log file and drawn some cards. Then I changed the visibility of a player hand, reopened the module as the other side and was able to check the hand without a problem.

Is that because it was an offline game? Does an online game (with passwords) checks the internal integrity of the a module?

This is a good question.

I have a module I’ve just completed and I want to test a similar function… the ability to “mask” pieces, and to make it verifiable by unmasking upon request/challenge. The thing is, while a piece is masked, even the owning player can’t see it until he (even momentarily) unmasks it. My question being, can the opposing player “watch” the owning player unmask the piece for that critical few seconds he needs to read it? And what about when exchanging files via PBeM? Can one “eavesdrop” while stepping through a log file?

Stilgr, my point is a bit deeper, manipulation of the module itself.

I my case, I have a “Out of the game” private window where used tokens go to and the player hands that are visible to the respective sides. Knowledge of the contents of either window is troublesome. In my test I was able to take a save game, open the module in the editor, change the visibility (and owners) of the private windows and hands and see everything without a problem.

The module is complete, but isn’t out yet, because I’m making these final tests.

I don’t think there’s much you can do here. In a live, real-time play situation, you can see the checksum of the module your opponent is using–if it differs from yours, that’s an easy tipoff that some modification has occurred. But you don’t have this in a disconnected PBEM setting.

I agree with JoelCFC25, also… play with people that you know don’t/won’t cheat. And refuse a game with a different checksum as yours.
I would say that overall, in the population of serious boardgamers, there are few cheaters.