A short story, a list of clues and a grid

Logic Grid Puzzles

A logic grid puzzle gives you a short scene, a few people and a list of clues. From those clues alone you work out who did what: who brought which dish to the potluck, who sat at which table, who paid how much. A grid of yes and no squares keeps track of everything you've learned.

Logic Grid Puzzles

Click a square once for ✕ (no match), twice for ● (match), three times to clear. Click a clue to cross it off.

00:00Time
0Matches
 Level

    Choose a level from the tabs above the board. There are 20 puzzles at each of easy, medium and hard, set at places like Karaoke Night, The Chess Open, The Seaside Hotel and The Vineyard Tasting. The stories and names are our own.

    How a logic grid works

    • Each puzzle has several categories. The first is always people's first names; the others might be a dish, a time, a price or an age.
    • Every person is matched with exactly one item from each category, and no two people share an item.
    • Every clue is true, and together the clues lead to one answer only.
    • In the grid, mark a cross where a pairing is impossible and a tick where it is confirmed. A tick rules out every other square in its row and column of that block.

    First moves

    Read all the clues once, then mark the plain ones: anything of the form this person did not do that becomes a cross straight away. After each new mark, look along its row and column. When only one square is left open in a row of a block, it must be a tick.

    Then link the blocks together. If Rosa ordered the soup and the soup was served at 7:00, then Rosa ate at 7:00, and if the soup was not on the patio, Rosa wasn't either. This carrying of facts from one block to another is called transitivity, and you'll use it on every puzzle, including the easy ones.

    Comparison clues hide a quick win. If one guest is older than another, the older one can't be the youngest and the younger one can't be the oldest, even before you know their ages.

    Sizes and levels

    A size such as 4×5 means four categories with five items in each. Easy puzzles are 3×4 or 4×4 and need only direct marks, rows that close themselves and transitivity. They are a good place to learn the grid, and many teachers use puzzles at this size with a class.

    Medium puzzles, at 4×4 and 4×5, add either/or clues (a person is one of two things), clues that pair two people with two items without saying which way round, cross-grid elimination and simple comparison bounds. Hard puzzles move up to 4×5 and 5×5 and bring exact differences (two dollars more, three years younger), adjacency, and comparisons you can only settle by checking the other person's remaining options.

    A 5×5 hard puzzle is close in shape to the classic zebra puzzle. For the toughest grids we make, where one step needs a short assumption followed to a contradiction, see the Einstein puzzle collection.

    Guides and printables

    The guide to solving logic grid puzzles works through a full puzzle and shows how each kind of clue turns into marks on the grid. It is worth reading once even if you have solved these puzzles in magazines, since it names the moves our levels are built on.

    Every puzzle can be printed from its page, and the printable logic puzzle packs gather several into one PDF with the answers on the last pages. Large print logic puzzles use bigger grid squares and clue text for easier reading.