Grid technique · Beginner
Last One Standing
When every option but one in a row or column has been eliminated, the survivor must be true, even if no clue ever said so directly.
Why it works
Every row and column needs exactly one yes. If every other candidate has been ruled out, the last one has nowhere else to go.
Trigger
A row or column with exactly one blank cell remaining and every other cell already marked no.
Common mistake
Scanning for clues that state a fact directly, and missing the forced marks the board itself is quietly offering.
Example
If four of five pets are already ruled out for Mina, the fifth is true, whether or not any clue ever mentioned it.