Renban Lines Explained in One Short Example
A four-cell purple line shows the renban rule. 5, 3, 7, 4 fails because the set skips 6, and 5, 3, 6, 4 passes because 3 to 6 is an unbroken run in any order.
Transcript
The rule
A renban line is usually purple or pink. Its digits form a run of consecutive numbers with no repeats, in any order. A 4-cell line holding 3, 4, 5 and 6 could read 5, 3, 6, 4.
The line's length fixes its spread. On a line of n cells, the highest digit is exactly n - 1 above the lowest, which limits how far apart any two cells can be.
Worth memorizing
A line of n cells holds n consecutive digits.
A 3-cell line could be 4-5-6 but never 4-5-7.
Every renban of 5 or more cells contains a 5.
Any run of five from 1–9 passes through 5.
If a line holds a 1, it runs from 1 up to its length.
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