I'm working on a game design which is to feature 'hidden' bidding. In this game players have secret victory conditions, which they strive to meet by placing 'bids' in the form of chips or cards at regular intervals in the game.
So I want player bids to be secret such that the other players will be kept guessing as to which set of victory conditions their opponents have.
There will be multiple ongoing bidding 'threads' at any one time, and bidding threads will be individually called to resolution by other game mechanics, and new threads will be started. Therefore bids will be made 'ahead of time', with the final outcome of a given bidding thread only revealed when the game forces a resolution of that bid.
My current scheme uses a set of chips, blank on one side and marked with one of two symbols on the other, representing a single negative point or a single positive point. When a player is eligible to make a bid of a certain size, he secretly selects chips of his choosing and deposits them in the relevant bag, so that no other players see whether his bid was positive or negative (or both, if he is trying to prevent his bid from easily revealing his desired outcome).
When the bid is resolved, the bag is turned out and the chips counted. More positive chips yields a positive outcome, and more negative chips yields a negative outcome.
The problem with the bag scheme is that I'd like it to be clear to players which ongoing threads have received the most bids, and the bag idea doesn't fit well with this. I could have players just make a stack of chips face down on the table, but one clumsy move and all would be revealed.
My other and more important question is whether anyone knows of any other games that have featured secret bidding mechanics, or whether anyone has worked on similar mechanics for their own games, since the geek doesn't have a catagory for hidden bidding.
Thanks for the feedback so far. I think that face down card bids seem to be the way to go, rather than chips. I'll just need to ensure the face down bids are shuffled together before being revealed to ensure that which way players bid is not obvious.
There will be plenty of visible information on the board. Additionally, the bidding will not be completed in one round, but will instead be built up as various players become eligible to bid on that thread (my current design has one pawn representing each bidding thread moving around on the board, picking up new bid cards on it's stack as various players move the pawn about in order to gain bidding opportunities).
However, JP - I'm mindful of your point about the outcomes seeming random, and would be interested how people feel about secret bidding in general as a game mechanic, especially since it seems that its not too common.
However I feel the hidden victory conditions could make for an interesting and tense game as long as there is sufficient opportunity for players to deduce the goals their opponents are working towards. Ideally all players would have deduced their opponents victory conditions at the start of the endgame, making the final part of the game a real race as the truth is finally revealed. In this game having open bidding is almost certainly going to preclude having hidden victory conditions.
FastLearner - I'd love to know what experiences you have had with this mechanic, and why it is up for elimination from your game.