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Comment by Pfhreak | Hacker News Reader

Interesting puzzle. I had to look up why the name was significant. The algorithm seemed pretty clear after a few rolls. Upon looking up the puzzle, I found I had a different algorithm than the one presented as a solution on wikipedia that resulted in the same output.

Edit: Which made the post's conclusion strange to me, if the name is not required to understanding the problem, why should Bill's interpretation be so surprising?

Edit2: Do people have other good examples of puzzles like this? I'm aware of Zendo [1] which is a similar inductive reasoning game.

[1] https://en.wikipedia.org/wiki/Zendo_%28game%29

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https://en.wikipedia.org/wiki/Eleusis_(card_game)

Found it in one of the Martin Gardner books.

Various rules I've found online:

https://boardgamegeek.com/boardgame/5217/eleusis

http://howell.seattle.wa.us/games/rules/Eleusis.html

http://www.bicyclecards.ca/game-rules/eleusis/189.php?page_i...

http://www.nhn.ou.edu/~kieran/eleusis.pdf

The rules vary, and all these seem different than what I read in Martin Gardner's article. A quick and easy version of it can be played with a single deck, sheet of paper (to record the rules) and 3+ participants (dealer + at least 2 players, more is better, too many needs more decks).

I'm curious what algorithm you came up with that yields the same outputs but isn't effectively the same. I could probably create a formula that doesn't directly reveal the key, but it would really just be an obfuscation of the real rule.

Edit: Actually, I see one other interpretation that relies on bqq if rira (minor spoiler). I guess if you arrive at this first, the name seems irrelevant.

Edit2: Rot13 for minor spoiler

Gur fhz bs gur frg bs bqq qvpr, zvahf gur pbhag bs bqq qvpr.

Wikipedia has a (short) list https://en.wikipedia.org/wiki/List_of_games_with_concealed_r...

I played a similar game with some folks once, but I don't know the game's name. The person who knew the rule(s) explained that there was a planet that was like Earth, but it only had a subset of the things that Earth had. We guessed different things on Earth, and the teacher would tell us whether or not this other planet had them.

Some samples include: Planet has apples, green grass, trees, runners, and cheese pizza. Planet does not have bananas, plants, people, hamburgers, cats, dogs, houses.

I won't put the rule(s) here in case people want to try it.

I know it as "In a Cool World..."

As in, "In a cool world, there is jelly but no bread", and, "In a cool world, we go skiing, but never snowboard."

I learned this as the Green Glass Door. Everything in the title is also valid to go through the green glass door.

Planet has summer but not winter, and fall but but not spring, right?

Yup! I remember my eighteen-year old self being pleased with "Planet does not have Audi, but it does have Audi TTs!"

Looking at it again, I think the game works better spoken than written out like this.

Probably so. Written makes it a lot more obvious.

Not exactly the same premise, but I've heard it called "Queen Anne Likes".

The name isn't required, of course. It's just a clue.

It arguably feels like a bigger accomplishment to deduce it from the clue. Kind of like a riddle.

Not exactly a puzzle, but a good game of Mao is always a fun challenge.

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