Hard technique

Obvious Triples (Naked Triples), Explained

Most sudoku guides call these naked triples. In Bubble Sudoku they are Obvious Triples.

When three cells in a row, column, or block show only three colors between them, those colors belong to those three cells. Remove them from every other cell there.

Read the block

BEFORE

This block has six open cells, and none of them shows a single color, so nothing can be placed yet. Look for three cells that use only three colors between them.

Find three cells with three colors

Look at the right column of this block. The top cell shows Orange and Light Green. The middle cell shows Orange and Dark Purple. The bottom cell shows all three. Three cells, three colors.

Remove those three colors from the rest

Orange, Light Green, and Dark Purple will fill those three cells. No other cell in the block can have them. Light Green comes off the two other cells that show it.

Place what is left

AFTER

The middle cell of the top row had Red and Light Green. With Light Green gone, only Red is left. Place it. The three cells in the right column are still undecided, and that is fine.

Cells being readKey cellColor tints match the color being followed

Key Insight

Not every cell in a triple needs all three colors. Here two cells show two colors and one shows three. What matters is that the three cells use only three colors in total. Start with two cells that show only two or three colors, then look for a third cell that adds no new color.

Related Techniques

Obvious PairsThe same idea with two cells and two colors, and the easiest version to spot.Hidden TriplesThe same pattern found from the other side: three colors that can only go in the same three cells.

If you’re stuck on a puzzle, see what to try next, in order.