Logic Grid

What is a logic grid puzzle?

A logic grid puzzle tells a short story about a few people and asks who is who: who keeps the parrot, who drinks tea, who lives in the third house. Every person has exactly one item of each category, and no two people share one. A list of clues gives the facts, and a grid of boxes lets you write down everything you work out.

Every puzzle here is made by a solver and has exactly one answer, reached by reasoning alone, never by guessing. There are three sizes, and every day brings a new puzzle, the same for everyone.

How to play logic grid puzzles

Read the story and the clues, then work on the grid. Each block of the grid sets one category against another: names against pets, pets against drinks, and so on.

• Crosses and ticks. Tap a box once for a cross (these two belong to different people), twice for a tick (they belong to the same person), a third time to clear it.
• Automatic crosses. A tick crosses out the rest of its row and column in the block, since each person has only one item of each kind. The Auto ✕ button turns this off if you prefer to draw every cross yourself.
• Clues. Tap a clue to strike it through once you have used it all up. On a small phone, the clues sit behind their own tab.
• The highlighter. The box you tap lights up its whole row and column, and the line under the buttons says what it stands for.
• Solution table. Under the clues, a table fills in as you tick names against the other categories. The puzzle is solved when the names' blocks hold every right tick.
• Hints and score. Your score is the time you take. A hint rubs out a wrong mark, or makes the next step for you and explains it in words, and adds 30 seconds. Undo is free. Each size has its own leaderboard.

Tips and strategy

1. Start with the plain facts. Clues like "Anna has the dog" or "the person with the cat does not drink tea" go straight onto the grid.
2. Every clue about two people is also a cross. "Ben lives to the left of the person who drinks milk" tells you Ben does not drink milk.
3. Carry ticks across blocks. If Anna has the dog and the dog owner drinks tea, then Anna drinks tea. Everything crossed out for the dog owner is crossed out for Anna too.
4. Mind the ends of the line. Someone who lives to the left of someone else cannot live in the last house; someone two houses to the right cannot live in the first two.
5. Either-or clues name two different people. If one of them is ruled out, it is the other one, and anyone who is neither of them is ruled out at once.
6. Look at what is left in a row. When every option still open for someone is crossed out against an item, that person is crossed out against it too.

Frequently asked questions

Is it free?

Yes. Like every game on Play, it runs free in your browser, with no download and no account.

Is this the Einstein puzzle?

It is the same kind of puzzle. The most famous one, often called the Zebra puzzle and sometimes credited to Einstein without any evidence, has five houses and five categories. The puzzles here are smaller, so that one fits on a phone, but they work the same way.

What does a hint do?

If a mark on the grid is wrong, a hint rubs it out first. Otherwise it makes the plainest next step there is, ticks or crosses that box, and explains why, quoting the clue or the boxes it comes from. Each hint adds 30 seconds to your time.

What do the levels mean?

Easy has three categories of four items, such as names, pets and drinks. Medium has four categories of four, and Hard four categories of five, with clues that need longer chains of reasoning.

What is today's puzzle?

Every day everyone gets the same medium puzzle, so times compare directly on the leaderboard. The names and words follow your language, but the puzzle is the same.