Summary:
Number Blocks (also known as Suguru or Tectonic) is a logic puzzle where you fill irregular cages with
the digits 1 through the cage’s size, once each, so that no two identical digits ever touch — even
diagonally. This tutorial explains the goal, the rules, and how to start solving.
Overview
In a Number Blocks puzzle the grid is divided into bold-outlined cages of different sizes and shapes.
Every cage of N cells holds the digits 1 through N, once each, and no digit may repeat in any of its 8
surrounding neighbours — even across cage lines. Some cells start filled in as givens, and every puzzle
has exactly one solution.
Number Blocks, Suguru, and Tectonic are the same puzzle under different names — Suguru is the original
name, Tectonic is the name it commonly goes by in Dutch puzzle magazines, and Number Blocks is not related
to the Numberblocks children’s TV series.
The Goal
Fill every empty cell with a digit so two rules hold everywhere on the board at once:
- Each cage of N cells holds the digits 1 through N, once each — no repeats, no gaps.
- Two cells that touch — including diagonally — never hold the same digit, even when they belong to different cages.
A cage with just one cell always holds a 1 — it’s the only digit a size-1 cage can have.
The Cages
Cages are irregular, connected groups of 1 to 5 cells — bold outlines mark where one cage ends and the
next begins. A single row can sit a 2-cage next to a 4-cage next to a couple of separate 1-cages; cage
shapes are not fixed to squares or dominoes, which is what gives Number Blocks its jigsaw-like look. The
bold cage borders are always thicker than the thin gridlines inside a cage, so the two are easy to tell
apart at a glance.
The Clues
Some cells are pre-filled with a digit — these givens are your starting point and can’t be changed. Every
other cell starts empty. Because a cage’s digit set is fixed by its size (a 3-cell cage always holds 1, 2,
and 3), the cage’s shape alone already tells you which digits belong inside it before you place a single
one.
How to Start Solving
- Read the cage sizes first — a cage of N cells only ever needs the digits 1 to N, so you already know its full digit set before you start.
- Fill in every 1-cell cage: it can only hold a 1.
- Look for a cell with only one digit it could legally hold, once you rule out digits already used elsewhere in its cage and digits sitting in any of its 8 neighbours. That’s a forced placement.
- Look inside each cage for a digit that only fits in one remaining cell of that cage, even if that cell still looks open for other digits too. For example: a cage still needs a 4 somewhere, and only one of its empty cells doesn’t already have a 4 sitting next to it — that cell must be the 4, even though it could still look like it has other options.
- If a digit’s only two possible cells in a cage both touch the very same cell outside the cage, that outside cell can’t be that digit either — one of the two cage cells is going to be it, so the outside neighbour is blocked either way, even before you know which of the two it will be.
- On harder boards, watch for two cells in the same cage that can only hold the same two digits between them (say, both could only be a 3 or a 4). Those two digits are locked to those two cells, so you can clear 3 and 4 from every other cell in that cage.
- Keep applying these checks until the grid is full; you never need to guess.
Difficulty and Guessing
Every Number Blocks puzzle — Easy, Medium, or Hard — has exactly one solution, and Puzzle Maker Pro
guarantees you can always reach it by logic alone. There is no “allow guessing” option, because none is
ever needed.
- Easy — every step is a plain forced placement (steps 2–4 above), and enough of the board is filled in that you rarely have to search for the next move.
- Medium — still forced placements only, but the givens are trimmed to the minimum, so you have to hunt for the next move.
- Hard — some steps need the two deeper checks above (step 5’s locked outside cell, and step 6’s locked pair of digits), especially on 8×8 boards and larger.
Outcome
You now understand the goal, the cages, the clues, and the first solving moves. Ready to make your own?
See How to Create Number Blocks Puzzles in Puzzle Maker Pro.
FAQ
Is Number Blocks the same puzzle as Suguru or Tectonic?
Yes. Number Blocks, Suguru, and Tectonic are the same puzzle under different names — Suguru is the
original name, and Tectonic is the name it commonly goes by in Dutch puzzle magazines. It isn’t related to
the Numberblocks children’s TV series.
What is a Number Blocks puzzle?
A logic puzzle played on a grid divided into irregular cages of 1 to 5 cells. Each cage holds the digits 1
through its size, once each, and identical digits can never touch — including diagonally — even across
cage lines.
Do the cages have to be square or a fixed shape?
No. Cages are irregular, connected groups of 1 to 5 cells — the same row can hold a single cell, a domino,
and a longer bent shape all next to each other.
Can the same digit sit diagonally next to itself?
No. No two cells that touch in any of the 8 directions around a cell — including diagonally — may hold
the same digit, even when the cells belong to different cages.
Does every Number Blocks puzzle have only one solution, with an answer key?
Yes. Every puzzle Puzzle Maker Pro generates is checked to have exactly one valid solution, and the
matching solved grid is generated alongside it as the answer key.
Do I ever need to guess to solve a Number Blocks puzzle?
No. Every difficulty, including Hard, is built to be solvable by logic alone — there is no “allow
guessing” toggle because it is never required.