Naked triples: reserve three digits in three cells
A naked triple uses three cells in one unit whose combined candidates contain exactly three digits. A cell does not need to show all three.
Key idea
Those three digits must fill those three cells, so the same digits can be removed from every other cell in the shared unit.
See the move, step by step
Read the 2, 3, and 6 triple at the start of row 4.
Step 1 of 4
Inspect restricted cells
Start with the cells in row 4 that contain only two or three notes.
Step 2 of 4
Take the union, not the intersection
R4C1 is {2,6}, R4C2 is {3,6}, and R4C3 is {2,3,6}. Together they use exactly three digits.
Step 3 of 4
Remove the reserved digits
R4C6 is outside the triple, so candidates 2 and 3 can be removed there.
Step 4 of 4
Keep only the remainder
R4C6 is reduced to 1 or 8 while the triple remains unresolved.
Try it on today's puzzle
For three cells in one unit, count the union of their candidates. Exactly three distinct digits—not three identical lists—is the condition.
Play today