Step 2 of 5
Sandwich
Sun, gap, sun: the gap can only be a moon.
The rule of thumb: Two matching symbols with one gap between them: the gap takes the other symbol.
Look for two matching symbols with exactly one empty cell between them. If that cell matched them, the line would have three in a row.
It’s Pairs with a hole in the middle, and easy to overlook because the two symbols don’t touch. These practice boards stall without it.
Where to look: Symbols two cells apart in the same line. When you place a symbol, look one cell past each of its neighbors.
Worked example
A real position from a board that needs Sandwich. Purple: what the reasoning rests on. Dashed: the cell in question. Green: what it proves (“this cell” in the text).
Gaps won’t fool you now. Next: stop looking at neighbors and count the whole line. Step 3: Balance →