The Doppit Almanac · No. 41
Pairit
Join every pair and fill the grid
What it is
Pairit is Numberlink. The grid holds pairs of matching numbers, and you join each pair with a line running cell to cell, up, down, left or right. Lines never cross, and no cell has two through it. Then the rule that makes it a puzzle: every cell ends up with a line on it. Nothing is left empty.
That last rule is what gives each board a single answer. Without it a line has room to wander and half a dozen routes are as good as each other. With it the board turns into one count: a numbered cell uses exactly one of its sides, every other cell exactly two, and one crossed gap in a corner can settle a line three cells away.
How it plays
- Join each pair of matching numbers with a line that runs from cell to cell, up, down, left or right.
- A line joins one number to its match, and no other number sits on it.
- Every cell of the grid has a line on it, and a dot marks a blank cell with no line yet.
- No cell has more than one line through it, and no line passes through a cell twice.
- On hard one number sits on four cells, and they join as two separate lines. On expert two numbers do.
- Draw puts a line across the gap between two cells, Cross marks a gap no line uses. Tap a gap, or drag along a run.
- Crosses are only your notes; the win ignores them. Stuck? Hint names the next forced gap.
The difficulties
Easy is seven by seven with seven to ten pairs, where two lines running to different numbers rule each other out across the board. Medium is nine by nine with a dozen pairs or more, and every board has a gap you settle only by following it to a contradiction. Hard is ten by ten, and one number sits on four cells instead of two, so which end belongs to which is a deduction of its own. A hard board wants about twenty of those contradictions and ten minutes. Expert is the same grid with two numbers on four cells each, and asks something the others never do: you suppose a gap, then a second inside the first before the board breaks. Every expert board wants a quarter of an hour. A fresh board is dealt every day, for nothing.
Play today's board