Numbrix is a puzzle game whose goal is to fill a squared grid with consecutive numbers following a horizontal or vertical path. At the beginning, the game displays the location of the highest and smallest numbers, as well as some other numbers that serve as clues to solve the puzzle.
Players use logic and memory skills to solve the Numbrix puzzle. Despite featuring numbers, math skills are not necessary. The first step to solving a Numbrix puzzle is to analyze the position of the clues, including the highest and smallest numbers. Players must look for cells in which it is only possible to write down a certain number. For example, suppose that number 1 is located on the upper left corner of the grid, and number 4 is located on its right. The only empty square that is adjacent to number 1 has to necessarily contain number 2. The second way to solve Numbrix puzzles is to try to imagine a possible path between two located numbers, to check whether that path leads to an impossible configuration of the grid. This may happen, for example, if the path isolates one cell in a way that no consecutive number can be put there. The aim of this strategy is to rule out impossible paths so to find the only possible path to solve the game.
Marilyn vos Savant invented Numbrix in 2008, and since then she has published a new Numbrix puzzle every week in the Parade magazine. The Numbrix puzzle is a variation of another logical puzzle, named Hidato. The main difference between Numbrix and Hidato is that the latter allows diagonal moves in the consecutive chain of numbers.