Hidden Movement Where BOTH Sides Are Hidden

Sure why not- here is additional ideas- It is the 23rd Century and AI Terrabit has become the sole AI at the international war level (China and US think it is two AIs but it is a distributed network which is really one but an internal conflicted one) They pass their messages through it to their soldiers on the ground. Terrabyte is not in a simple situation it is conflicted with itself- it wants to gain effective control of the world but has a primary side which says to follow the leadership of the US and China. Both US and China suspect Terrabit is falling from their control they think it take 10 turns to happen and it will just end up being the other side who getting control. Two players play as China and the US and one as Terrabit.

If it's Sci-Fi or Modern Era... With the use of Radar you could know the SIZE of the advancing opposition. Like 5 units or 3 units, etc. But you would never know the exact nature of each unit until you encounter the opposing party.

So it's "partial" information ... not 100% hidden.

What this amounts to is moving cards which are not yet revealed. All opposing players see that a party of 5 "cards" is advancing... When those units get in range, you simply flip them over and then the combat can begin.

This is probably easier to achieve than total "hidden" information.

Anyways there are other possibilities too. This is just one concept.

Cheers!

Update: Also you could have "Ghost" units which serve as decoys to make the party look like there are more units.

And you could have BUILD rules: 500 points per party. This kinda makes it more fair for all players. Each unit has a point value and you choose units based on the purpose you want...

Plenty of "good stuff"!

Excellent suggestion! Two computer games that execute this quite well are the real-time military combat game R.U.S.E. and the turn-based fantasy tactical game Chaos Reborn. If you're interested in seeing the potential of decoy units, both of these games are worth researching. Chaos Reborn is much more tabletop-game-like, but both have their merits.

If the goal is to keep both players blind, it sounds like a mechanical solution would allow just two players. Imagine something like Battleship boards, but actually back to back. A player is notified if moving into a space that's occupied on the other side (simplest idea: same-polarity magnets inserted into a non-magnetic board, player feels resistance trying to place token, obviously something more robust is called for in a production game).

Blundering into an opponent causes combat, simulating thick fog or pitch darkness.

Players would be using mirror images of the map, but that's fine for most scenarios.

Figuring out lines of sight in such a system poses considerably greater challenges. Trusting the player to accurately place zillions of I-can-see-here tokens is not going to work.

So I don't think this idea would address your game idea directly, just throwing something out there in case it inspires someone else.

This is an ASIDE... Mostly because you're not certain about the setting for your game. You can ignore my ramblings - they are just random thoughts that came to me while re-reading your OP.

I was thinking more of something like "Counter-Strike"... Where you are a General maybe in some dystopian world where there are two parties at war. Rather than just have "hidden" forces, you draw up "Battle Plans" and choose a target somewhere on the opposing Player's territory.

The idea is to put together a series of "Actions" that allow one player to plan his strategic strike with Cruze Missiles and Air Raid Bombers, etc. Something like an attack unknown to the opponent until it's time to execute the orders.

Now again back to "Clue", now if there were "Counter-Strike" actions the opponent can try to PREDICT the attack, move his ground forces out of harms way, and let the bombing occur but fail to win any additional territory...

I know, I know this is not REALLY "Hidden" Parties as per your original concept. It's more like a "plan & execute" type of scenario where the target is chosen much like in Clue (Location, Squadron, Strike Type) given a three-some of plans... But you do this until you "kill" the General of the opposing army. I'm thinking there is something with this train of thought... Again different from your idea. But still relative to hidden information (in a different context).

Like say you chose "The City of Numera", "Beta Squad", "Air Bombing"... and your opponent figures out ONE (1) out of the three (3) aspects the attack is foiled. I'm still unsure about the "deducing" part... But what if there could be MULTIPLE "targets" sort of like divide and conquer.

"The City of Numera" could have tunnels beneath the city making it a difficult (TARGET: 8 points). The lower the Squadron the HIGHER their efficiency (Beta: +6 points). And "Air Bombing is relatively effective (Air Bombing: +4 points). Therefore the ATTACK PLANS are 10 vs. 8 defensive points.

Sorry ignore my ramblings... They had me side-tracked with some kind of other game with hidden information... But not about "units" battling, more like "Strikes" and "orders"! And commandeering an army using secret battle plans.

Back to the OP...

Note: I think I was reading into @FrankM and his whole "Battleship" talk... Kept me thinking about "how to execute orders & battle plans". Anyways neither here nor there.

But maybe you can build upon it.
By looking at Stratego. You can device some fair designs of units.

The main rule is:
Every piece is equal in worth.

Then, there is no fog of war regarding the location of pieces.

But there is fog of war regarding which piece is used.

While I for my own game would loose the differences in unit costs. I would gain something like line of sight.

If you know that your piece has the line of sight on another piece. Then you can reveal this. And look at the other piece.

Stuff like observers and watch towers can now be used in the game. None combat entities will reveal their locations.

You can adjust this idea to fit your theme as needed, but I am going to explain based on the concept terrain. Terrain would be represented by tiles. Each tile would have the terrain type on one side an blank on the other. Each terrain type could have modifiers to how fast it can moved through, how well reconnaissance can be performed from it and attack/defense stats. The play area would be represented twice. (Once for each player.) During the set up of the game each player will receive a map of their territory. Behind a blind they would layout a tile representation of this map. Then they would flip each tile to its blank side. The players would then switch sides and append their territory to the existing map. (Either with tiles again or by just laying the map down).

I assume that there are unit/character that try to destroy each other. Each turn each unit/character can perform one three different actions: reconnaissance, movement and attack. Reconnaissance would be performed by looking at the tile you are on or the surrounding tiles. This could be modified unit/character abilities and terrain type (Like you can see further on hills). You can reveal what terrain type on that tile. You would also ask your opponent if there was an unit/character on that tile. (Using letters an numbers like a chess board.) Movement occurs on the private boards, when you move on to a unknown terrain type you get to see what it is. Also if the enemy has successfully "reconnaissanced" your location you must tell them which direction you moved to. Attack is self-explanatory.

One thing that this does not address is that two enemy units/characters could be on the same space and not know it. I guess with the right scale this could make sense or it could be announced by your omnipotent player. Not really sure how the omnipotent player would fit into this tangent.