-Slitherlink is a logic puzzle is played on a rectangular lattice of dots. Some of the squares formed by the dots have numbers inside them. The objective is to connect horizontally and vertically adjacent dots so that the lines form a simple loop with no loose ends. In addition, the number inside a square represents how many of its four sides are segments in the loop.-(Hashi) Each puzzle is based on a rectangular arrangement of islands where the number in each island tells how many bridges are connected to it. The object is to connect all islands according to the number of bridges so: There are no more than two bridges in the same direction. Bridges can only be vertical or horizontal and are not allowed to cross islands or other bridges. When completed, all bridges are interconnected enabling passage from any island to another.-(Futoshiki) Place numbers of the given range in the grid 9x9 such that every row and column contains each number exactly once. Inequality constraints must be satisfied. The open end of the sign denotes the greater number.-Numbricks puzzles are similar to Hidato. The most important difference is that it is only possible to move 1 node left, right, up, or down. It is played on a rectangular grid of squares. Some of the cells have numbers in them. The object is to fill in the missing numbers, in sequential order, going horizontally and vertically only. Diagonal paths are not allowed.