Sudoku variant · rules and tips

Between Lines

The digits on a between line must lie numerically between the two circled endpoints. If the endpoints are 2 and 7, the cells along the line may hold 3, 4, 5 or 6. The circles set the boundaries; the line lives within its means.

Get it onGoogle PlayPlay Between Lines on the web
Professor Cryptic, the owl who teaches in the app
Professor Cryptic explains the rule

The Professor's tips

How do you solve Between Lines?

01 / Warm up

Start on a 4 by 4 grid

  • The endpoints define a range, and the range defines the line. Endpoints of 1 and 4 leave only 2 and 3 available.
  • Settle the endpoints before anything else, since they govern every cell along the line.
  • If the endpoints are consecutive, nothing at all can lie between them. Either the line is empty or one of your endpoints is wrong.
02 / Level up

Then try a 6 by 6 grid

  • A wider range lets more sit between. Endpoints of 1 and 6 leave 2, 3, 4 and 5 available.
  • Knowing one endpoint limits the line; knowing both settles it. Solve the circles early and the rest follows.
  • A line crossing a box boundary tells you twice as much, since its digits must satisfy both the between rule and the box.
  • Long lines are the most constrained of all. Every cell must fall within the range, and none may repeat within a row or a column.

The rule, drawn

What does Between Lines look like?

  1. Between Lines rule illustration, step 1 of 2
  2. Between Lines rule illustration, step 2 of 2

Start with a single square

Where can you play Between Lines?

Between Lines is one of the 17 variants in Cryptic, each with a lesson and unlimited puzzles.

Get it onGoogle PlayPlay on the web