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A puzzle whose solution is a methodological plan of action for realizing a specific goal.

21
votes
2answers
369 views

lolcatz can haz ur infinit cheeseboard

This is a problem on an infinite chessboard with pieces called lolcatz. They can move like queens or knightriders, but have a strange disadvantage... ... you've never heard of knightriders? Well, ...
0
votes
3answers
213 views

Rullo solving strategy for 2-4

How to eliminate/nominate candidates without guessing? For the 3s it's quite easy because of the odd numbers but how to get further?! For thoose who don't know the game, here's a short introduction:...
1
vote
1answer
125 views

Master and Slave versus Bob: easy version

Continuation of: "Sub-puzzle: Master and Slave versus Bob the Violent but Honest Psychopath" Continued in: "Master and Slave versus Bob: hard version" Previously I described a game that is played ...
0
votes
1answer
134 views

Master and Slave versus Bob: hard version

Continuation of: "Sub-puzzle: Master and Slave versus Bob the Violent but Honest Psychopath" and "Master and Slave versus Bob: easy version" The hard version is identical to the easy version (see ...
1
vote
3answers
235 views

Sub-puzzle: Master and Slave versus Bob the Violent but Honest Psychopath

[I created this as a sub-puzzle to "Strategy to beat the Casino reversed", that has been sitting unsolved for months. You may wish to read that puzzle first, but this is self-contained. My answer to ...
6
votes
1answer
132 views

Another 'Find the Path' Puzzle

Based on user477343's Find the Path puzzle I have produced a slightly larger puzzle based on a similar mechanic. Goal is as follows: Draw a continuous path between the two red dots. The path must ...
8
votes
4answers
247 views

A “Find the Path” Puzzle

I invented a puzzle, inspired by Simon Tatham's Portable Puzzle Collection. Is there anything that it could improve on? Was it too easy, or was it too hard? Anything I could add? What must I call it? ...
16
votes
2answers
294 views

If you have 3 random numbers between 1 and 27 can guess the fourth?

Problem: Ashley and Ivan want to impress their friends and come up with a magic trick: One of their classmates comes up with 4 unique random numbers between 1 and 27 and tells them to Ivan. Ivan ...
1
vote
1answer
57 views

How to make a 2v2 rotation with 5 people

I'm running a volleyball club at school and we currently have 5 active members. Is there a way of having everybody play in a duo with everybody else and have one person sit out each game practising? I ...
1
vote
0answers
48 views

Are there basic weighing puzzles requiring adaptive strategies?

Let us define a basic weighing puzzle as such: There are <number> identical balls, except one weighs <more/less/a different amount than the others> A balance scale may be used to weigh two ...
3
votes
4answers
213 views

Classic 2 Guards But With 3 Doors Instead

So the rules are almost the same : You get to ask just one question to whichever guard you want to (just 1 guard; asking both guards is not allowed) There are 2 guards, one tells the truth and ...
0
votes
0answers
58 views

Best strategy for Multiple Blindfolded 3x3 Rubik's Cube event (WCA)

The MBLD event is quite hard on the technique and the memory , testing the 3x3 Blindfolded method. The cube placement strategy as discussed by few officials stand at : Cube Placement The other ...
1
vote
2answers
618 views

Strategy in Coloring a 4x4 empty grid and the one who completes any 2x2 area of the grid is the loser

Alice and Bob are playing the following game: They have a 4x4 empty grid and take turns coloring one square each, starting with Alice. Assume that both players will colour the squares in with the same ...
7
votes
6answers
660 views

Single-pile Nim with Three Players

Three perfectly rational logicians (Alice, Bob and a Quetzalcoatlus) are playing a game. (Charlie couldn't make it, so he asked the Quetzalcoatlus to fill in for him.) The rules are very simple: ...
2
votes
5answers
321 views

A Very Odd Game

Barry, John, and Caleb, all perfect logicians, were very bored one day and they decided to come up with a new game (they haven't got a name for that game yet). The rules were quite simple : The first ...
2
votes
2answers
247 views

Radioactive River

You, Alice, Bob, Charlie, Daniel, Elisa, Fred, and Greg are playing a cooperative game called Radioactive River. They have to get across a 20 meter carpet/radioactive river, and they only have: 3 ...
11
votes
6answers
677 views

I Have To Be With Them!

It's almost time for another year of school! But before school starts, Principal Little needs to form classes. Because there are so many people in a class, the parents are always complaining, asking ...
11
votes
3answers
310 views

Guffin factory regulated heist

I work at a guffin factory. I manufacture guffins and have an unlimited access to guffin storage. I can fit up to 20 guffins in my bag, get them home from the factory and nobody will chase me. You ...
1
vote
2answers
243 views

Solution or Origin of logic puzzle

This is not my puzzle and I do not know the solution. This was shared to me by a friend. Their former boss told them this riddle. I was told this question originated from Steven's Institute of ...
2
votes
1answer
595 views

$\verb|Eight Circles|$

An entry in Fortnightly Topic Challenge #37: Rare and Endangered 1 Materials Pencil; Eraser; Blank A4 sheet of paper; and A ruler (also to use as a straightedge). Puzzle: Draw a square with a side-...
7
votes
1answer
199 views

Domino Tiling Game

Two players are presented an $n\times n$ grid. They take turns placing a piece on the board until no more moves are possible. The last player able to make a move is the winner. The pieces are $2\times ...
12
votes
4answers
3k views

A dice game, what is the optimal strategy?

Alice was walking on the street when she came across a man playing with a die. She could not help trying to check if the die was loaded and while she was concluding that it wasn't loaded, the man ...
8
votes
1answer
432 views

Clearing the Robot Museum

The grand opening of the Collapsible Robot Museum is just 1 week away in the robot nation of Robotia. The museum is unique because shortly after the museum closes, the building collapses into a flat ...
0
votes
6answers
439 views

Data Sharing Between 3 Players [closed]

Consider a situation in which two companies hold data about individuals: the first company holds individual's names, and their age. The second company also holds the individual's name, but instead of ...
29
votes
3answers
934 views

Snakes on a Plane!! 2

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Inspired by the title of this xkcd comic, but in no way related or affiliated beyond the shared name. It's a well known fact that any ...
8
votes
4answers
386 views

Ten users, three lights but it's a chatroom

This is a variant of the classic problem of m prisoners n lights. (Example may be found here but note that the requirements are not exactly the same) The goal for you, however, is different. You want ...
2
votes
0answers
109 views

Ten users, ten deadly collars and three lights [duplicate]

One day, 10 puzzling.SE users, including you, find yourselves in a horrible prison. Each of you has a deadly collar, presently lethal. It is safe to take off only when all of the 10 collars have been ...
7
votes
5answers
377 views

Two person game, choosing an integer between 1 and 30?

Suppose two players are playing a game. The first player chose an integer, n st. $n \in \left\{ 1,\ldots ,30\right\}$. The second player picks a different one. After that, a random integer x st. $x \...
3
votes
3answers
174 views

Optimal number of weightings in marble problem

Consider $N$ pieces of marble. The pieces of marble look identical to one another. One of the pieces is heavier than the other. In other words, out of the $N$ pieces, $N-1$ have the same weight and $1$...
5
votes
3answers
448 views

Foolproof double betting

Just made up a problem. Have ideas, but no proof yet – came here for professional help. Tonight an important match of Metagame (box/football/baseball/chess) takes place. Everyone is hyped. Everyone ...
3
votes
1answer
243 views

Variant to Minesweeper

The following game is a variant of minesweeper: There is a 7 by 7 grid of squares. Each square either has a skull or a number indicating the number of squares containing skulls surrounding that ...
4
votes
1answer
165 views

Find the fake bar in 2 weighing [duplicate]

You are given 8 equal sized bars of silver labeled a to h. You know for a fact one of them is fake, and the only measurable difference is weight. However you do not know if the fake bar is heavier or ...
12
votes
3answers
478 views

Strategy to beat the Casino reversed

Let's consider Strategy to beat the Casino puzzle, but reverse it - fix number of losses and ask a question about amount of rounds: Two players, A and B, and the Casino play a game. The game ...
-4
votes
1answer
134 views

What did the Wise Man Say? [duplicate]

An Arab sheik is old and must will his fortune to one of his two sons. He makes a proposition. His two sons will ride their camels in a race, and whichever camel crosses the finish line LAST will win ...
5
votes
3answers
245 views

Crazy queen in checkers

Checkers Checkers, also called draughts, is an interesting game. all pieces are placed on black tile and are all pawns at the start. When a pawn reach the final line, a powerful piece is created: the ...
17
votes
4answers
3k views

A Tic-Tac-Toe type game

I found this interesting game with no name: You have a 1x11 grid, like this. The way you play is similar to Tic-Tac-Toe (aka Noughts and Crosses). Players take turns to place Xs and Os on the grid, ...
4
votes
2answers
231 views

How many nodes in the network?

I don't actually have a solution in mind for these, but it seemed puzzly enough to bring to the table. Seems as though someone must have come up with this before, but if so, I couldn't find it when I ...
5
votes
3answers
1k views

Hacking an electronic keypad v2

This is related to Hacking an electronic keypad. You are a spy trying to break into an enemy facility. The back door is protected by an electronic keypad lock. You know that this particular lock is ...
5
votes
2answers
693 views

How much money can we make? v2

This is follow up question to How much money can we make? My five friends and I used to loan each other money all the time. But over the past several years we have moved apart. We don't trust ...
8
votes
1answer
395 views

General strategies for solving metal disentanglement puzzles

(When I talk about metal disentanglement puzzles, I have in mind Hanayama and Tavern puzzles.) As opposed to twisty puzzles - which I can approach by playing with commutators and conjugates as a way ...
2
votes
5answers
443 views

Word game - possible to play all words?

You're trapped in a chamber and the only way out is to beat the chamber guardian on his own game: Word88. Both of you each take a turn to play a word. You can play one of the following: Add Play - ...
17
votes
10answers
1k views

Communicating Information about Cards

Seven cards, numbered $1,2,3,4,5,6,7$, are distributed randomly among three people: Rand gets one of them, Deusovi gets three of them, and Gareth gets three of them. All three know what the seven ...
15
votes
2answers
2k views

10 prisoners and 10 lists of numbers [duplicate]

10 prisoners are held captive by a cruel warden. One day he gathers them in the prison hall and tells them about a new game he wants to play: "Tomorrow, I will assign each one of you a random ...
8
votes
4answers
830 views

The Greedy Box (Or: Another crazy guard offering his prisoners freedom)

Two prisoners, in separate cells, are watched over by one eccentric and whimsical guard. One day he (inevitably) decides to give the prisoners a chance to earn their freedom by playing a game with ...
5
votes
1answer
323 views

Another Secret Polynomial

Alice: Let's play a game, Bob! Bob: (sighing) What is it this time? Alice: I'm thinking of a polynomial $P$ with integer co-efficients. For any integer $n$, you can ask me what $P(n)$ is. Then, if,...
8
votes
3answers
403 views

Gettings most jewels in a square 5x5

Playing an online game I came across a small puzzle (a mini-game in game). The game is about getting jewels in a row - a player needs to get 5 in a row / column or a 5-square-diagonal. Let me show you ...
7
votes
2answers
396 views

99 chips into more chips V2

This is follow up question of 99 chips into more chips, which is originally: You are at a casino in Vegas and you have earned 99 chips by playing poker! While you are checking out a slot ...
8
votes
1answer
2k views

99 chips into more chips

You are at a casino in Vegas and you have earned 99 chips by playing poker! While you are checking out a slot machine, someone comes to you and congratulates you that you have a chance to make more ...
6
votes
3answers
367 views

The Alchemist's brew

I'm an Alchemist and I want to prepare Universal Panacea. That's a precious thing and I will be able to sell it for good money. The complete recipe for the Panacea is of course very complex (and ...
38
votes
7answers
5k views

Amnesiac in a ring shaped palace

Related: Turn off all lights in a ring-shaped palace Your boss has trapped you inside a ring-shaped palace, and all you know about the palace is that there are some number* of identical rooms, each ...