A logic problem grid is a graphical representation of all possible combinations of answers to a logic puzzle. Solvers use the grid to eliminate incorrect answers and determine the correct ones.
Grid-based logic problems typically feature a story having three to five categories. A one-to-one correspondence exists among the category items. The solving grid lists each variable across the top of the grid and again down the left side. There is a column and row for each option within a category, except that the first category on the left has only rows and the first one along the top has only columns.
The solver uses the puzzle clues and reasoning to determine which item in one category goes with which item in another category. The solver makes a mark in each box to show that a combination is eliminated and another kind of mark to show a match between items.