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Procedural Hidden Information Mechanics

8 replies [Last post]
Joined: 01/24/2010

Now thats a mouthful.

What I am interested in is everyone's take on hidden information mechanics. More specifically I am trying to think of a good way to produce a mechanic that allows for something to grow while hidden, but in a very procedural manner.

As an exercise, lets imagine this scenario. We have various locations on a map, some of which are infected. The players do not know which locations are infected and cannot see these infected locations until they actually come across them.

So far, this is a pretty easy mechanic to develop, right? Just have some cards, or chits that have Infected/Uninfected on one side, and the other side is a ?. You can even include a "level" of infection to show how bad it is.

The problem is trying to produce a system where that infection grows and spreads over time logically/procedurally without the players knowing it. If you have an infected placement at a location on the map and the players do not get to it in a certain amount of time, how do you spread that infection to surrounding areas without tipping the players off if they are not in those locations?

Of course we need the initial placement of ground zero (or patient zero) to be random on the map board.


Joined: 04/18/2009
I do not think it can be

I do not think it can be done. There is always one thing missing.

If it starts in a and grows that I think can be done as you said with relative eas. But to have it spreadind without another player controling it can not be done unless you have rules for how it spreads. And that is also fine the onley problem is you have to check the ground zero al the time to know it it has spread so you have to know exactly how bit it is. Every time you go to a new location you would have to check on groundzero to se if it have reached there yet.

So the onley way to solv it I would say is to have a player controling it. Or atleast that would be the easiest and simplest way.

You might be able to do it if you have a preprogramd grothpattern that is random on the map but grows exponentialy over time. Think of it as a mix between pandemic and a traitor game.
You place the groundzero marker in a city. The first turn you take a deck of cards, the deck consists of infe3cted and not infected cards and the dificultylevel is in how manny you have of each, you deal out one of thees cards to every adjacent city. The next turn you do this again but this turn you also deal one card to the citys that are next to al citys with a card, also you put in more infectd cards. This way you have "hidden" information, ither the city is infected or not. Also when you go there you take ths stack of cards and flipp them over, this way you have the oldest card first. Now you go throu it to se if and when it was infected. Then depending on when you know how bad it is now, like it was infected 4 turns ago so now half the city is infected or somthing simular. This way you will have a spread from groundzero and a logical groth. And maby you can add a "if the city have 5 cards it is infected" even if al of the cards says uninfected, or you have a valu on the uninfected cards and you tally up thoes and when they reach a certan number the city is also infected, this way you can have new "random" outbraks simulating people going from the groundzero there. The random number should be withing a prity narow span and the players should be awar of what the avarage number per card is so they can do rufguesses of when the citys should be infected. This way you can have the players arguing about if they should go and save it now or wait, it might not be infected yet we do not know for shore and so on. The biggest thing about a game like this I would say is how you design the map.Becaus if you do a airspread virus then the map is a limiting factor for the players sort of simulating reality. And if you do a human to human virus then ot spreads along the same paths making it a difrent game, one with more strategy in it. "what city should we go ti first, this one that have bin infected the longest or this mor strategic one. From here the virus could spread out to numurus other citys" This can be done using a river or mauntain range as a natrual obsticle onley alowing the virus and players to cross it on sertan locations.

Atleast that is what I would do.

Joined: 12/15/2009
This is a really tall order.

This is a really tall order. It sounds better suited to a computer game than a board game.
It might be possible to somehow do the dynamics "backwards" by making rules which force new information to be consistent with previously revealed information and the dynamics of the disease. This would be equivalent to hidden information, but it wouldn't actually be hidden: it would be randomly determined when revealed.

larienna's picture
Joined: 07/28/2008
I read your thread rapidly,

I read your thread rapidly, if I understand correctly, you want infection to spread but you actually don't know if there is enough infection tokens in the stack to actually spread since the information is hidden.

I have 2 solutions which has their pro and cons.

A- When a player visit an area he reveals the tokens, if the infection level is too high, it will spread to neighboring cities. The problem is that players could prevent themselves from exploring a location knowing it will explode. So you might need mechanic to force players to visit unvisited cities.

B- After a certain number of tokens, whatever is their content, the infection spread. Use the law of average. If 1/2 of your token increase infection level by 1 and you need 5 level for the infection to spread, in average, if you have 10 tokens in a location, you should have reached level 5. So either you reveal the token and spread the infection for leave the tokens there and add new tokens in the adjacent areas.

You can also combine both mechanics if you want.

Joined: 01/03/2010
Hidden Infection.

I don't post often but I simply MUST respond to this one because I think I have the beginnings of an elegant solution.

So the goal is to have logical "viral" style expansion on a game board, but which is completely hidden from the players, as I understand it. There are several components of information being dealt with here. One is the location of "ground zero," and this you want hidden. The second is the rate and pattern of spread, and this you also want hidden. Sense the spread happens over time, the third component of the information is the number of turns that have transpired so far in the game. This piece is NOT hidden.

What you need to do is find a way to hide the two HIDDEN pieces of information TOGETHER, and then then tie them to time elapsed.

You need a turn order counter of some sort, not hidden; and that's quite easy. Then you need your card / token. These will reveal where ground zero(s) is/are, and have to describe: a) The LEVEL of infection, dependent on proximity to ground zero, and b) the PROGRESSION of the infection over time.

Now it becomes clear, you really only need three numbers on this token. One number is the "threshold," and this number determines how many squares from ground zero the token can be and still count for anything. Instead of a number some of the tokens will display "G" and in that case it IS one of the ground zeros. The next is the level of infection - this much strength is added to the infection IF the threshold requirement is met. The third number is how often the score is counted - every turn, every two turns, etc.

So for instance, I have a stack of tokens on a location which I now must reveal for some reason. It is turn 4. I reveal a token with: Threshold 3, Strength 2, Time 2. This token is located 2 squares away from ground zero, so it is under its threshold and thus activates. Sense it is turn 4, I count this token's Strength twice. So this token adds 4 to the Strength of the infection at this location. Higher thresholds will be rarer than low ones so that more tokens will count closer to ground zero than further from. All the tokens are placed on locations during the course of your game (or they could all be placed at once at the beginning, it really doesn't matter) and then at the end they are revealed simultaneously, forming a cohesive, complete "web" of information defining exactly one correct data point for each location.

During the course of the game maybe players can reveal or alter some of these tokens. But they won't always mean what the players may think! For instance, a player might get the chance to flip a token and find a Threshold 4, Strength 3, Time 1 - a very strong token. The players may work hard to destroy or alter this token before endgame, only to find out upon revealing everything at endgame that the location was a very unlikely 5 spaces away from any ground zero, and the token would not have activated anyway!

The only constraint to this system of hidden information is that the tokens are meaningless at single locations. Because of how they interact, ALL the tokens must be revealed before the web of information is complete.

Pastor_Mora's picture
Joined: 01/05/2010
Reverse Pandemic, Tobago Style

DogBoy wrote:
This is a really tall order. It sounds better suited to a computer game than a board game. It might be possible to somehow do the dynamics "backwards" by making rules which force new information to be consistent with previously revealed information and the dynamics of the disease. This would be equivalent to hidden information, but it wouldn't actually be hidden: it would be randomly determined when revealed.

I like DogBoy's approach. I'll have information revealed BY the players TO the players as they manage to fit it in a consistent chain of information previously revealed.

I've seen all kinds of debates on virus expansion mechanics since Pandemic. If I could afford the time, I'll work in twisting the virus game backwards. That is, working on a "containment" mechanic instead of in a "contagion" one, not done by the game, but by the players.

So, here's the example. Say a plague spreads in the country and you have to contain it by sanitizing (¿english?) every city in the board. Use the Tobago mechanic. During his turn, a player uses a card with a certain condition discovered about the virus ("cannot live in coastal environments", "cannot tolerate high temperatures", "requires heavy population density"). This will progressively reduce the "endangered cities" in the map, untill all cities are safe from the disease. Voilá! problem solved.

I tried to keep it short. Hope this makes sense. Keep thinking!

SiddGames's picture
Joined: 08/02/2008
Possible Solution

Okay, I'll take a stab at it. This would only be feasible if the number of potential ground zero sites was fairly low.

Suppose you have a map with many cities, but only 6 are potential ground zero sites, and only 2 will be actual ground zero sites. You make 6 stacks of spread tokens. 4 stacks are full of harmless tokens and 2 stacks are full of infection tokens. Randomize the stacks so you don't know which 2 are infected (this might be hard, heh -- easier using cards rather than tokens), then assign them to the 6 potential ground zero sites.

Every turn, add a token to the site. When a site has X tokens (say 3), then you start adding a token to each adjacent site. Continue this process.

When a player investigates a city, shuffle the tokens there before revealing them. If it's all clean, then you can deduce that each city that spread to that site is not a ground zero. If some are infections, then you have narrowed down the potential ground zero, etc.

I think it would work with a little tweaking, but not sure how elegant it is without seeing it in action.

Clay's picture
Joined: 08/30/2010
this will take a few pieces

For this idea you will need a tile for every single square on the board. But I think this would work.

Lets say there are 100 spaces on the board.
So then you have 3-5 ground zero tokens and 15-25 infected tokens.
Shuffle the tokens and place them face down on the board.
When a player moves over/to a space flip all touched tokens over.
If the player runs into an infected token then they suffer the consequences (whatever they may be, attack/movement minus etc...)

For every ground zero token flipped ALL infection tokens increase by 1: they are now able infect 1 square out in every direction.

So that by the end of the game each infection token extends out 3-5 spaces around it.

I know it's not a true "ground zero" expansion pattern. sorry about that

Joined: 01/24/2010
Thanks for input

I want to thank everyone for their input on this. A lot of very good ideas here.

Im of the opinion that the most elegant solution would be to develop a "reverse procedural fillin" method based on given information.

Seed the board with hidden "possible" ground zeroes. Or even simply call them infection points. Have a time tracker in place. As time goes on, the potential "pool" of infection grows. Once an infection point is discovered, have a system that backfills from the pool that has grown and begin placing on the board (can be logarhithmically developed, as you will always find the edge of an infected area before finding its core unless it has not spread beyond the core).

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