Hide/Reveal specific pieces from/to specific players

Here’s what I’m trying to do:

  1. Have at least two “Umpire” player positions
  2. 6 players that are “kind of” on the same side (say, Red and Blue), but they can’t see what their “cohorts” are doing UNTIL an umpire decides they can see their units.
  3. Further, any of those units, individually, must be able to be revealed to any number of the individual players on the other side!

If you haven’t guessed, this game is “Kriegspiel”, using rules of hidden units, order-passing, and orders delay. I plan on using the notes window for passing orders.

I’ve seen some different ways of hiding units from non-owners. That’s as easy as the “invisible” trait. Unfortunately, I need to be able to reveal and hide from specific players, if that helps.

If this is just impossible to do in Vassal, I need to know ASAP, so I don’t waste time going down the rabbit hole.


Curt Pangracs
Directorate of Simulation Education
Army University

After a sleepless night of mulling over this question, I may be going about this the wrong way. Perhaps a better question is, can I have any number of “hidden” player maps that specifically belong to each player, and can these maps (all the exact same map as the “umpire” map) somehow combine views on one specific map, and further, can any of these hidden maps be shared with another, specific player at will by another player, like the Umpire?

IOW, can these different maps exist, with single instances of a player’s assigned pieces, and those pieces ALSO exist on a single specified map board simultaneously, and can units be selected for reveal to specific players at-will?

I see now why there is no version of Kriegspiel already available for Vassal…

At this time, I don’t think VASSAL has the features you need for your use case. Crucially, access by certain player sides to private windows can’t be altered at run-time…whatever list you configure in the Editor, that’s what you’re stuck with. The ability to mask or render things invisible both have settings for who can manipulate that–any player, any side, any of some specified sides. But that’s not the same thing as “reveal this piece only to side X, chosen from a list of eligible sides”.

That’s what I was trying to find out, and confirms my concerns with Vassal as the engine for this type of game format.

I think something could be hacked together, but I am not familiar with the game, so I can’t be sure.

Private maps and traits on pieces that place an identical piece on it and send the piece to another map. When the source piece moves, it sends a command moving the mirror piece to the same coordinates. This could be done for all pieces, some pieces, to any number of maps.

I’m sure it would be a headache coordinating everything.