Futoshiki is a logic puzzle game from Japan. It is also spelled hutosiki (using Kunrei-shiki romanization). The puzzle is played on a square grid, such as 9 x 9. The objective is to place the numbers 1 to 9 (or whatever the dimensions are) such that each row, and column contains each of the digits 1 to 9. Some digits may be given at the start. In addition, inequality constraints are also initially specified between some of the squares, such that one must be higher or lower than its neighbour. These constraints must be honoured as the grid is filled out.

Straights is a logic puzzle. It is a grid, partially divided by black cells into compartments. Each compartment, vertically or horizontally, must contain a straight - a set of consecutive numbers, but in any order (for example: 2-1-3-4). The aim is to fill all white cells with the numbers from 1 to N (where N is the size of the grid). No single number can repeat in any row or column. Clues in black cells remove that number as an option in that row and column, and are not part of any straight.

Numbricks - kind of logic puzzle. It is a rectangular grid in which some cells are numbers. Required to fill the empty cells so that all the numbers have been connected in series horizontally or vertically. Moving diagonally is not allowed.

Suguru ("Number Blocks") is a logic puzzle invented by Naoki Inaba (Japan) that has simple rules, but which provides sufficient challenges to satisfy the most enthusiastic solvers . The task consists of a rectangular or square grid divided into regions. Each region must be filled with each of the digits from 1 to the number of cells in the region. Cells with the same digits must not be orthogonally or diagonally adjacent. Even though the rules are simple, you will need all your skills to solve it.

The Battleship puzzle (sometimes called Bimaru, Yubotu, Solitaire Battleships or Battleship Solitaire) is a logic puzzle based on the Battleship guessing game. Each ship occupies a number of contiguous squares on the grid, arranged horizontally or vertically. The boats are placed so that no boat touches any other boat, not even diagonally. Numbers alongside the grid indicate how many squares in a row or column are occupied by part of a ship. In Battleship, an armada of battleships is hidden in a square grid of 12x12 small squares. The armada includes 1 battleship five squares long, 2...

Calcudoku (also known as -Mathdoku-) is a mathematical and logical puzzle loosely similar to Sudoku. It was invented by a Japanese mathematics teacher Tetsuya Miyamoto. The objective is to fill the grid in with the digits 1 through N (where N is the number of rows or columns in the grid) such that: - Each row contains exactly one of each digit. - Each column contains exactly one of each digit. - Each bold-outlined group of cells (block) contains digits which achieve the specified result using the specified mathematical operation: addition (+), subtraction (-), multiplication (), and division...

Sujikai (literally -diagonal-) is a variation of Sudoku. The puzzle consists of a triangular grid of cells containing digits from 1 to 9. The objective is to fill a grid with digits so that each cell contains a digit and no digit is repeated in any column, row and diagonal in any direction. Also, no digit occurs twice in any of the three larger 3 x 3 square regions and any of the three larger triangular regions enclosed by thick borders.

Hidoku (from Hebrew: -my puzzle-) is a logical puzzle. The goal of Hidoku is to fill the grid with consecutive numbers that connect horizontally, vertically, or diagonally. In every Hidoku puzzle the smallest and the highest number are presented in the grid. There are more numbers on the board to help to direct the player how to start the solution and to ensure that Hidoku has only a single solution.

Sudoku Mine combines Sudoku puzzle with Minesweeper game. The goal is to place three mines in every row, column and region. The digits in the grid represent the number of mines in the neighbouring cells.

Kakuro (also known as "Cross Sums," "Kakro") is a logic puzzle, a mathematical equivalent of crosswords. The puzzle consists of a playing area of filled and empty cells similar to a crossword puzzle. Some black cells contain a diagonal slash from top left to bottom right with numbers in them, called "the clues." A number in the top right corner relates to an "across" clue and one in the bottom left a "down" clue. The object of a kakuro is to insert digits from 1 to 9 into the white cells to total the clue associated with it. However no digit can be duplicated in an entry. For example the...