The computer starts with all the lights off, but then clicks 3, 4 or 5 times at random, leaving some lights on. Can you switch them off again?

Advent Calendar 2010 - a mathematical game for every day during the run-up to Christmas.

A game for 2 players. Take turns to place a counter so that it occupies one of the lowest possible positions in the grid. The first player to complete a line of 4 wins.

Everthing you have always wanted to do with dominoes! Some of these games are good for practising your mental calculation skills, and some are good for your reasoning skills.

A game for two people, who take turns to move the counters. The player to remove the last counter from the board wins.

A game for 2 people. Take turns joining two dots, until your opponent is unable to move.

An ordinary set of dominoes can be laid out as a 7 by 4 magic rectangle in which all the spots in all the columns add to 24, while those in the rows add to 42. Try it! Now try the magic square...

A Sudoku with clues given as sums of entries.

Solve this Sudoku puzzle whose clues are in the form of sums of the numbers which should appear in diagonal opposite cells.

A game for 2 players. Can be played online. One player has 1 red counter, the other has 4 blue. The red counter needs to reach the other side, and the blue needs to trap the red.

A game for 1 person. Can you work out how the dice must be rolled from the start position to the finish? Play on line.

A game for 2 players. Given a board of dots in a grid pattern, players take turns drawing a line by connecting 2 adjacent dots. Your goal is to complete more squares than your opponent.

This article for teachers describes several games, found on the site, all of which have a related structure that can be used to develop the skills of strategic planning.

A game for 2 players that can be played online. Players take it in turns to select a word from the 9 words given. The aim is to select all the occurrences of the same letter.

Help the bee to build a stack of blocks far enough to save his friend trapped in the tower.

The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.

Four Go game for an adult and child. Will you be the first to have four numbers in a row on the number line?

Square It game for an adult and child. Can you come up with a way of always winning this game?

Nim-7 game for an adult and child. Who will be the one to take the last counter?

Unmultiply is a game of quick estimation. You need to find two numbers that multiply together to something close to the given target - fast! 10 levels with a high scores table.

A shunting puzzle for 1 person. Swop the positions of the counters at the top and bottom of the board.

An article for teachers and pupils that encourages you to look at the mathematical properties of similar games.

Exchange the positions of the two sets of counters in the least possible number of moves

Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.

A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.

Can you work out how to win this game of Nim? Does it matter if you go first or second?

An extension of noughts and crosses in which the grid is enlarged and the length of the winning line can to altered to 3, 4 or 5.

This challenge is a game for two players. Choose two numbers from the grid and multiply or divide, then mark your answer on the number line. Can you get four in a row before your partner?

Can you use the numbers on the dice to reach your end of the number line before your partner beats you?

Can you spot the similarities between this game and other games you know? The aim is to choose 3 numbers that total 15.

Throw the dice and decide whether to double or halve the number. Will you be the first to reach the target?

Can you make the birds from the egg tangram?

In this article for teachers, Liz Woodham describes the criteria she uses to choose mathematical games for the classroom and shares some examples from NRICH.

Use the tangram pieces to make our pictures, or to design some of your own!

Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.

A game that tests your understanding of remainders.

Here is a version of the game 'Happy Families' for you to make and play.

A game for 2 players. Using 2 dice, some counters and a games board, can you form a line of counters from one side of the board to the other?

A game to make and play based on the number line.

An activity based on the game 'Pelmanism'. Set your own level of challenge and beat your own previous best score.

Work out the fractions to match the cards with the same amount of money.

Take it in turns to place a domino on the grid. One to be placed horizontally and the other vertically. Can you make it impossible for your opponent to play?