Inductive reasoning games (Eleusis, Zendo)

[Simon]

Hi folks,

I've always been interested in inductive reasoning games, where you have to guess an overall pattern from examples.

The most prominent games here are Eleusis and Zendo. Both have a games master (god, master) think of a secret rule. All other players (scientists, students) carry out experiments, which are marked by the master as conforming to the rule or not. Th scientists's main task is to guess the secret rule governing this marking.

In Eleusis, players take turns adding playing cards to a central sequence. Here's a writeup of how I've played it. The secret rule governs which cards fit onto the end of the current sequence. Invalid plays are placed to the side of the current sequence's end, to remind people later on that this card didn't conform to the rule at that point.

Scientists win if they empty their hand of cards first, and must draw replacement cards for invalid plays. If someone feels pretty sure about the secret rule, he can declare himself prophet and judge other people's plays before the god does. Judging correctly allows the prophedt to discard additional cards from hand, but judging incorrectly leads to a severe penalty of extra hand cards.

In Zendo, as described on the excellent Zendo website by its designer, no sequence is built. Instead, predefined building blocks (Icehouse pieces) are arranged in various manners, each such arrangement is called a koan. The master marks koans as conforming to the rule or as not. There is no penalty for testing nonconforming koans. The goal is to formulate a rule that is equivalent to the master's rule, i.e., the master cannot build a counterexample that satisfies only either the guessd rule or the master's rule.

Would people be interested in this as a forum game? Unless tons of people discourage me from this, I'm going to start a forum game thread soon. An alternative is to play on IRC.

What might be the best forum game rules? One standard method on the net seems to play Zendo with words, i.e., arbitrary strings of characters [A-Z]. Customly made Lemmings levels are also possible, but too unwieldy to build in large quantities for a forum game. ;-)

I'd play without turns, so everybody can simply post test cases for the master to mark, and guess rules, which can lead to a win or a counterexample. Testing cases should be free of penalty (0 points), or almost free (-1 point). A false guess should only bring about a minor penalty (-10 points) compared to guessing the correct rule (+100 points or something).

-- Simon

[NaOH]

I'd be down for Eleusis or Zendo, although I have spotty internet access here so I probably wouldn't be able to contribute much. The idea of playing with custom Lemmings or Lix levels is particularly appealing, though, as that might inspire some creative new lemmings levels. It would probably be a long-term endeavor, though.

I saw your comments on IRC about Eleusis last night, which reminded me of another game I play often (usually with cards) called Mao. In Mao, players take turns placing a card from their hand to form a sequence. There are a series of pre-defined rules determining whether a card matches a sequence, although these rules tend to differ between groups of players. If a player breaks a rule, they withdraw their most recently-played card and, in addition, draw a new card from the deck. Otherwise, once a player has successfully discarded all their cards, they get to come up with an additional rule and they draw five cards and continue playing. (In some variants, the entire game starts over with the additional rule.) These rules may add to or subtract from the options available to players, or do both, so rules may accumulate over time without bringing the game to a stand-still. The nature of the rule is kept secret by the player who authored, so it is up to that player to award card penalties for infractions. (Indeed, in many variations, the initial set of rules is kept a secret by God and the players who are familiar with them already.)

I think that's a decent explanation but I'm a bit rushed to post My vote is still for custom-level Zendo, as impractical as that may be.

[mobius]

I'm hip but extremely busy at the moment so I'll play when I can. I also have to read the rules first. This time I didn't even read to know what the game actually involves. But if past mafia was any indication that won't effect my playing ability very much   

[Simon]

Alright, game thread with simple rules coming up in a day or two. :-)

NaOH: Yes, Mao fits right in this category. My gripe is Mao's metagame: The scope of rules isn't as clearly defined as in other games, and it's important to know what has happened in earlier games. The rules knowledge between games is not the same for all players. The game feels like an inside joke, occasionally very entertaining for regulars, but hard/forbidden to explain the game to newbies in its exact current form.

Eleusis seems to me like the cleaner implementation of the same principle. This is highly subjective, I've met players who have enjoyed Mao very much.

möbius: The beauty of turn-less Zendo is that you can't disturb anything by posting whatever you want, with or without knowing the rules. You can even discuss hunches about the secret rule with others, then it turns from a competitive game into a collaboration puzzle, which is just as enjoyable.

-- Simon

[Ramon]

Wow, Eleusis sounds really cool (at least from the page you wrote up), and I'd definitely join. Haven't read up Zendo yet because ime flalling aslep liek amost tis minnut :p

[Zaphod77]

There is a general set of starting rules that is used by most groups for Mao, with slight variations depending on who it was learned from.  The main rule is you aren't allowed to explain the rules, even outside the game, only to penalize infractions.  Everyone learns by trial and error.

But since we can't play this over the forum anyway, the game is like crazy eights. Objective is to empty your hand, and you follow rank or suit, drawing if you can't or don't wish to play, and playing the card just drawn if able to. Certain cards have special effects, like Uno. There are wild cards, skip cards, reverse cards, draw cards, and a few other rules stuffed in to make things interesting.  Which cards have which effects varies a bit.

Some variants have a HUGE number of initial rules. These variants you can explain the rules before the game, but once it's started the rules may no longer be asked about.  These ones tend to have every single rank  of card have a special effect.

Yes, the game is a really good way to torture new players, who end up thinking it's all just a big conspiracy and rules are just being made up on the spot to torture them, but once everyone knows the basic ruleset, the game becomes fun as you try to stump other players with your new rules, and they just keep piling up and pretty soon everyone is screwing up, talking when not required to by the rules (which earns a penalty card) swearing (which earns a penalty card, plus the penalty card for talking), laughing (which earns a penalty card) and when someone is about to win one mistake can easily earn a large number of penalty cards.

If someone actually wants to spring this on their friends, PM me and i'll explain a basic ruleset, and some very common variants.  It IS possible to introduce new players without being a jerkass.  Let them watch for a bit, then give them a seven card penalty for "watching without playing".

[Simon]

The small genre of induction games got another entry in 2020.

Visitor in Blackwood Grove

Homepage
Rules as PDF
Design History
Boardgamegeek entry

Secret rules are about physical objects that are printed on cards, and the secret rule classifies each object as passing or not passing. Secret rules may not consider the spelling of the objects or insider information.

Basic flow of Visitor: The alien visitor creates a secret rule. The kid and the alien are on a team; they win if the kid is the first to guess the rule. They play against the government agents who are not in a team with each other; each agent is playing for himself.

At first, the agents receive information faster than the kid, that's why the alien doesn't want to create too easy a rule. Late in the game, the kid learns information much faster, that's why the alien wants a rule of medium difficulty. But if the game takes too many rounds, the agents win by default, that's why the alien doesn't want too hard a rule.

An oddity from their design history: "in my experience games of Zendo always end in the rule maker saying “Your guess is close enough.” " -- My (Simon's) experience is to the contrary; such fuzzy endings are rare in Zendo. And they should be rare if one plays by the rules as written. Either the master can imagine a counterexample, then he must build it, or he cannot. There is no middle ground. Sure, "Close enough" can occasionally happen when the master bakes an arbitrary fixed physical length or angle into the secret rule, which is theoretically impossible to learn by bisection in normal Zendo play. But such rules are rare, and they aren't that good in the first place. Groups of players should naturally drift towards playing fewer rules with exact measuring in physical units, and towards logically clearer secret rules. Certainly, groups should not end every Zendo game with "Your guess is close enough."

Nonetheless, the design history (link above) is fun to read, with solid ideas.

-- Simon