1. Treating a likely option as confirmed
A cell can look more plausible than the others without being proven. In a logic grid, probability is not enough: O belongs only on a forced or directly confirmed match.
One premature O can create a chain of false X marks and corrupt the whole grid.
2. Failing to propagate O
Finding a match and immediately moving on wastes information. Eliminating competitors after O often creates several new forced situations at once.
3. Reading clues in isolation
Individual clues may look weak. The real power comes from combining the consequence of one clue with information in another category and then linking it to a third clue.
4. Forgetting to rescan the grid
If you return only to the clue list after every mark, you can miss a row that now has one remaining option. The grid itself becomes a source of new information.
5. Over-marking X
Marking X because a pairing 'seems unlikely' is simply guessing in negative form. Every X also needs a reason.
6. Mixing up category pairs
With several matrices on screen, make sure a deduction is recorded in the correct category pair. A valid fact entered into the wrong matrix can make the puzzle appear contradictory.
7. Ignoring contradictions
If a row has no option left or two items are forced into the same unique slot, stop. The grid is telling you an earlier mark was wrong.
- Check recent O marks first.
- Trace the X marks generated by those O marks.
- Review the last two or three deductions.
- Do not add another guess on top of a contradiction.