Build one fence around a field. Numbers are dotted about the grid; they are all inside the field, and each one says how many field squares it can see if it looks up, down, left and right, counting itself. The fence blocks the view.
The field must be all one piece, and it can’t have holes — every square outside must be able to reach the edge of the grid without crossing the fence.
Choose squares and the fence draws itself around them, so you can concentrate on the logic: a 2 next to a 5, a number squeezed into a corner, a square that can’t be reached.
Fence in one field so that every number is inside and sees exactly that many field squares across and down.
The full guide, with a worked example and common mistakes: How to play Fenced Field.
Yes — a number sees itself, so the smallest possible number is 1.
Yes — the fence can run along the edge.
Yes — every puzzle is checked so that logic alone finds the field.