KEEP IN MIND
- A matching adjacent pair restricts its neighbors.
- A pair with one gap forces the middle color.
- A complete line has equal color counts.
- Completed rows differ; completed columns differ.
Begin with the no-three rule
Look for two matching tiles side by side. The open cell immediately before or after that pair cannot match them. Then look for a matching pair with one gap between: red, empty, red forces the middle to blue. These deductions work in columns as well as rows. After placing a tile, inspect both crossing lines.
Use the size of the board
A completed line contains half of each color. On a four-cell row, a pair of red tiles uses the entire red allowance; any remaining cells must be blue. On a six-cell line, the allowance is three. Count all existing tiles in the line before making the deduction, including ones separated by gaps.
Compare a nearly finished line
Suppose one row is complete and another would become identical if its final choice were red. The second row must differ while still satisfying its color count and no-three restriction. Apply the same test to columns. This rule is easiest to use after simpler local deductions have reduced the options.
Build a repeatable scan
As a solving habit, scan rows for pairs, scan columns, then count nearly completed lines. Finally compare similar lines. This sequence is editorial advice for organizing attention, not a required move order. If a placement creates a contradiction, return to the deduction that produced it instead of changing several unrelated cells.
Keep the two companion games separate
0h n0 also uses red and blue marks, but its clues count visibility. The equal-color and unique-line constraints belong to 0h h1. When switching games, read the opening tutorial again; their similar appearance can make an old rule feel familiar even when it no longer applies.
