Bored with the current selection of puzzles? Brighten your logic skills by giving Light Up a try!
The square grid in a Light Up puzzle is inhabited by empty cells and walls. Solving the puzzle is done by determining where to put the lights so that every empty cell is lit.
Each light illuminates all empty cells to its north, east, south, and west, as far as the light can reach. Walls block light, so other lights may be needed to light up the cells on the other side of each wall.
Furthermore, in the world of this puzzle, there is a fundamental problem with one light shining on another. No two lights can be placed in the same row or column, unless there is a wall between them. In a way, it makes sense. Two lights lighting up the same row or column, when only one is required do the job, is inefficient. Like most logic puzzles, the solution here is all about efficiency.
Some walls grace the puzzler with clues; these numbers indicate how many lights are in the cells adjacent to that particular piece of the wall. In Light Up, diagonal cells are not considered adjacent.
The trickiest part about Light Up puzzles is that not all lights are indicated by clues. Many lights will not have a clue near them, or even a wall. Usually, the last few lights of a puzzle are the hardest to place, because there may be multiple configurations that illuminate the rest of the unlit cells. However, in these cases, it is important to remember that the correct solution always uses the fewest number of lights.