Logic-grid fundamentals
10 Logic-Grid Puzzle Strategies for Beginners
Logic grids become manageable when every mark records a fact rather than a hunch. These ten methods help you organise the clues, avoid common errors and reach the one arrangement that satisfies the entire puzzle.
Begin with the facts that cannot move
Scan the clues once before filling anything in. Start with direct matches, direct exclusions and fixed positions: a named person used a named object, an event happened at a stated time, or two categories cannot belong together. These marks create the frame for every later deduction.
- Use one symbol for confirmed matches and another for exclusions.
- Complete the corresponding row and column after every confirmed match.
- Treat ‘before’, ‘after’ and ‘next to’ as relationships, not exact positions unless the clue says so.
Use all ten strategies
The core techniques are: direct match, direct exclusion, one-to-one completion, either-or pairing, ordering, adjacency, transitive deduction, category linking, contradiction testing and final verification. A difficult puzzle rarely requires a secret trick; it requires two or three ordinary rules to be combined without losing track of what each one proves.
- If A equals B and B excludes C, then A excludes C.
- If every option but one is eliminated, the remaining option is confirmed.
- If an assumption produces two matches in one row, reject the assumption.
Work in passes instead of rereading randomly
On the first pass, enter only explicit information. On the second, complete rows and columns. On the third, combine ordering and relationship clues. On the final pass, test unresolved pairs. This prevents you from repeatedly reading the same dramatic clue while overlooking a quiet but decisive restriction.
- Number the clues and note which one justified each important mark.
- Pause whenever a confirmed match does not produce new exclusions.
- Do not guess to make the grid look complete.
Verify the story as well as the grid
A completed grid is not automatically a correct solution. Read every clue again against the final arrangement. In a murder mystery, also check that the identified suspect had the required opportunity, route and access. The solution must explain all evidence without creating a second possible arrangement.