Questions tagged [game]

A puzzle that asks for determining the winner in a multi-player game.

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14
votes
3answers
900 views

Twenty coins and no balance

On the table there are $20$ coins that carry the letters $A,B,C,\ldots,T$. The values of these coins are $1,2,3,\ldots,20$ Euro (but the assignment of values to letters is secret). Fredo knows the ...
4
votes
1answer
891 views

Optimal game of Bluff (not the wikipedia one)

Rules Basics 52 well shuffled cards are dealt equally to both players. Player 1 starts the first hand. The game consists of a number of rounds, which are played as follows. On each round, players ...
10
votes
3answers
932 views

Pop the Last Bubble

Having bested the silly clown, you go to your packaging job. It is a slow day, so you decide to teach the game you learned to one of your coworkers. There are no balloons around, so you use bubble ...
11
votes
4answers
1k views

Pop the Last Balloon

A clown approaches you, holding 99 red balloons. He proposes a game where the two of you will take turns popping some nonzero number of balloons. The only restrictions are: On the first turn, the ...
10
votes
1answer
759 views

Let's revisit this later (a two player knight's game)

Alice and Bob play a game on the following irregular chessboard. (Note the blacked out squares are not legal moves.) Alice starts the game by placing a knight on any square she chooses. They then ...
8
votes
4answers
546 views

Blackboard problem with polynomial

The blackboard contains the two numbers 0 and 120. Each minute you are allowed to write an additional number $ x $ on the blackboard if $ x$ has not been written before on the blackboard and if $ x $ ...
30
votes
3answers
4k views

A lonely pawn on the chessboard

Alice and Bob and the referee Conny play the following game with a pawn on a standard $8\times8$ chessboard: In the beginning, Conny places the pawn into the center of a randomly chosen square. All $...
6
votes
2answers
781 views

A prime number game

Alice and Bob play the following game on a $9\times11$ chessboard. First Alice divides the chessboard into $33$ smaller rectangles of dimensions $1\times3$ and $3\times1$. Then Bob labels each of ...
13
votes
3answers
2k views

The knight's game

Alice and Bob play the following game on a standard $8\times8$ chessboard. In the very beginning, Alice picks a square on the chessboard and places a knight on this square. Then Bob and Alice ...
18
votes
2answers
2k views

Blackboard cleaning

The blackboard contains 30 integer numbers from 1..2000. Each minute you are allowed to elect some positive integer number x and subtract x from some (chosen by you) of the numbers on the blackboard ...
11
votes
2answers
727 views

Ninety-nine non-negative numbers

Alice and Bob play the following game with $99$ numbers $M_1,\ldots,M_{99}$. In the beginning, the $99$ numbers take the values $1,2,4,8,16,\ldots,2^{97},2^{98}$. Then Alice and Bob alternatingly ...
3
votes
3answers
353 views

Rock-paper-scissors

Sheldon, Leonard and Wolowitz play a sizzling game of rock-paper-scissors for three players. In every round, each player simultaneously shows one of the three shapes. Rock beats scissors, scissors ...
59
votes
5answers
9k views

How to beat Count Dracula

Abraham Van Helsing and Jonathan Harker play a game against Count Dracula. The three players agree on the following rules: Count Dracula and Van Helsing enter the crypt, while Jonathan Harker ...
6
votes
3answers
421 views

Five-hand poker

Both players are dealt $26$ cards from a regular $52$ card deck. He discards $1$ and makes $5$ hands (from the remaining $25$) in any order, each with $5$ cards. His score is given by the sum of ...
1
vote
7answers
362 views

The Buzzer Game [closed]

Two players, A and B, are each given air horns. Also present is a device which will at some random point produce a noise. If the device produces a noise before either player, they die. If both players ...
10
votes
4answers
807 views

Alice, Bob and Carol, and many cookies

Alice, Bob and Carol sit around a round table. Initially Alice has $n$ cookies, while Bob and Carol have none. Alice divides her cookies evenly between Bob and Carol; if there is a leftover cookie (as ...
6
votes
2answers
892 views

Non-Greedy Chocolate Eaters

A variant of Greedy Chocolate Eaters (created by my significant other, who doesn't like chocolate all that much) Alice and Bob are playing a game with a rectangular bar of chocolate scored into $m \...
15
votes
9answers
2k views

The Trickster's Game

While walking around the streets of your local city, you encounter a strange woman sitting atop a gigantic pile of dollar coins. "Would you like to play a game?" she asks. Intrigued by the strange ...
10
votes
3answers
833 views

Greedy Chocolate Eaters

Alicia and Bobby play a game with a rectangular chocolate bar, scored into an $m$ by $n$ grid of squares. The children alternate turns, with Alicia going first. On a child's turn, they must break ...
13
votes
4answers
893 views

Golden Pancakes

Alice and Bob play a game with two stacks of fluffy, golden pancakes, of sizes $p$ and $q$. They alternate turns, with Alice starting. On their turn, a player must eat some number of pancakes from ...
11
votes
6answers
4k views

Unsolvable static minesweeper puzzle? (+ 3D twist!)

You have an $m$ by $n$ rectangular grid. Each cell may contain a single bomb or a number (or neither, but not both). If a cell has no bomb and is adjacent (horizontally, vertically or diagonally) to ...
12
votes
3answers
5k views

Chomp (Game with a Poisoned Chocolate Bar)

In the game of Chomp, two players start with a chocolate bar, which is scored into an $a$ by $b$ array of squares (where $a\cdot b>1$). The square in the lower left is poisoned. The players ...
10
votes
4answers
1k views

Rocks and Lever (Game) - Goofspiel

I am not sure if there is a name associated with this game but I do not know of one. There was this 2 player game I had once played, and I am wondering if there is a winning strategy. The game is as ...
7
votes
2answers
605 views

Alternate Face Up Poker with Alice and Bob (on the floor)

I was so convinced that the "correct" answers to this excellent question were wrong that I took out a deck of cards to prove it. Then I realised that I was changing one of the rules. So here's the ...
30
votes
3answers
3k views

Face Up Poker with Alice and Bob

Alice and Bob are going to have a poker night. They have invented a variant where there are no secrets, and no randomness, called Face-Up Poker. Here's how it works. A standard 52 card deck is ...
7
votes
1answer
865 views

The Triangle Game

Take an equilateral triangle with dots at the vertices and at the midpoints of each side: There are a total of six dots. In the triangle game, you have the numbers 1, 2, 3, 4, 5, 6. Place one number ...
4
votes
1answer
602 views

Generalisation of Nim

I'm asking for a general formula/algorithm that can be used in such a game. There are $n$ piles, with varying number of pebbles. The number of pebbles in each pile is given by an array from $pile[...
14
votes
3answers
1k views

eXtreme Nim: A Game With *Lots* of Pebbles

Two children are playing a game with several piles of rocks. Each turn they do the following: They choose some pile of rocks. They count how many rocks are in this - let this be $n$. We remove this ...
11
votes
1answer
468 views

Dim - A Game with Pebbles

Alice and Bob play a game with a pile of $n$ pebbles. They take turns, with Alice going first. On their turn, a player can remove any number of stones from the pile which is a proper divisor of the ...
6
votes
2answers
558 views

Unsportsmanlike Aliens

It was the first meeting of the humans and the aliens, and things were going well: The humans and aliens had learned to understand each other's language and found that both were hoping for a peaceful ...
26
votes
4answers
2k views

Lions and Zebras on a Chess Board

The black knight is our lion chasing 8 white bishop zebras which can't capture. Can the zebras evade the lion forever, if team zebra positions all the pieces and has the first turn? Rules: The game ...
21
votes
3answers
8k views

Knight on a 5 by 5 board

Alice and Bob play a game with a $5\times 5$ chessboard, and a chess knight. Alice begins by placing the knight somewhere on the board. Then, starting with Bob, the players alternate moving the knight ...
8
votes
6answers
1k views

Devious auction game

Saw this on TV today: A man is auctioning a real $20\$$ bill. There are a vast number of bidders. A person may make as many bids as he wants. The starting bid is $5\$$. No $2$ bids must be ...
3
votes
2answers
1k views

Game against the Devil

While browsing through S.E you notice a spider crawl right out from under your keyboard! Startled, you twitch your hand and left clicked your mouse. You look up in shock as you notice that you just ...
10
votes
1answer
318 views

Blessings of Ares

Two gladiators are about to do battle in the coliseum. Before the battle, they enter separate rooms and pray to Ares, the god of war. Ares blesses them each with random amount of power, which you can ...
3
votes
3answers
526 views

Two knights jousting on a chessboard

Two knights (black and white, the latter going first) start on opposing corners of a chessboard, moving across it in the usual manner, attempting to capture each other: the knight who first lands on ...
3
votes
2answers
845 views

Unsolvable sudoku net with maximum blocks

Definitions For a $9\times9$ grid $G$ (not necessarily respecting sudoku rules), a subset of cells $S$ is defined to be sudoku-friendly if the values in $S$ do not contradict the rules of sudoku. ...
12
votes
2answers
2k views

Checkers with the devil

After however much inordinate time passed for the tree-pruning game to finish, you ended up winning, and Satan was infuriated. He was sure he'd come up with a game keep you in hell. But once again, ...
8
votes
4answers
2k views

Thirteen coins game

There are $13$ coins arranged in a circular fashion. Andrew and Bill play a game with these rules: Andrew starts the game A player can remove $1$ or $2$ adjacent coins from the circle during his turn....
11
votes
4answers
2k views

Tree-pruning game with the devil

You won the coin-flipping game against Satan, but being the devil he is, he decided that that game was much too easy, and reneges on his promise to let you go. Instead, he gives you a new, more ...
78
votes
8answers
12k views

Coin Flipping Game with the Devil

You die, and awake in Hell. Satan awaits you, and has prepared a curious game. He has arranged $n$ quarters in a line, going in the east/west direction. He placed the coins at the ends tails up, and ...
7
votes
1answer
794 views

2 bishops versus a lone king

There are 4 pieces on the board, the white and black kings, as well as 2 white bishops (on differently colored squares). The only way a stalemate occurs is if the black king is not in check, but ...
8
votes
1answer
1k views

Hangman- No misses left

**** No programs allowed. You must find the answer using your own brain. **** Your hangman game allows for 9 misses, but on the 10th miss, you're hanged! You don't want to be hanged. The letters ...
7
votes
1answer
851 views

A Game with Strings and Coins

Alice and Bob play a game using the following arrangement of coins, which are joined by strings and hanging from the ceiling: $\qquad\qquad\qquad\qquad\quad$ The two alternate turns, with Alice ...
8
votes
3answers
1k views

Coin inverting game

Header and Tailer play the following game. At the beginning, the juror lays out a row of $n\ge5$ coins on the table that alternately show heads and tails, with the leftmost coin showing heads. ...
2
votes
3answers
235 views

Drawing squares

Anafenza and Zurgo are playing a game. They have a playing board of $23*92$ squares. The idea of the game is to put a square(of any size) onto the playing board. The one who can't put any more ...
12
votes
3answers
1k views

Who wins the AI-game?

Anna and Isadora play a game by writing letters on the blackboard. In the first round, Anna starts by writing down the letter $A$ or the letter $I$. In the $n$-th round with $2\le n\le 999$, Anna ...
1
vote
1answer
676 views

Eat sweets and start your own business!

The manager of the local sweetshop, one Minty Ball, has announced a grand closing down sale. They sell $n$ varieties of sweets: toffees, sherbets, fudge, and so on. Let's just call the varieties $V_1,\...
10
votes
3answers
2k views

Precision Tag - can the lion win?

This is a spin-off motivated by Lopsy's interesting variant of Gamow's lion and zebras puzzle. It arose from a line of enquiry that tried to extend the vertical run past 5000km (or characterise the ...
37
votes
6answers
3k views

The subtraction game

Alice and Bob play a game that starts by Bob picking a secret integer $N\ge100$. Then the game goes through several rounds. In every round, Alice picks an integer $x\ge3$. Every number can be picked ...