Shatterline

A geode sawn flat and hollowed into a board. 9 pockets in the rind, 5 crystal teeth against 4 shard clusters, and one straight line of three to settle it.

Set, pieces in
5.5 × 5.1 × 1.3 in
All 10 parts
3.3 oz
The finished set: nine crystal pieces seated in the pockets of a brown printed board, five purple towers and four mint-green clusters.
A finished game, left where it ended: the teeth have the front row, and the last piece went into the pocket on the right.

Tic-tac-toe lives on napkins because it costs nothing to draw.

Give it weight and it behaves differently. A piece lands in its pocket with a knock you can hear, the board keeps the position until somebody lifts the pieces out, and a game that ended an hour ago is still sitting there being an object. The whole set is one printed board and nine printed pieces — no hinges, no magnets, no printed grid lines, nothing that can go flat.

One game, 9 moves

A boulder sawn flat and hollowed out. Scroll: the nine pockets fill one piece at a time, and the game that plays here is the one the pieces are for.

9 pockets, 36 mm apart, ribs 6 mm wide between them. Three in a row in any direction ends it — which is why the middle pocket is worth more than the corners.

A piece drops in at any angle. The foot is a Ø28 mm disc, the pocket a Ø30 mm hole: 1 mm of clearance all round and nothing to line up.

Teeth opened in a corner, clusters answered in the middle. After that it is mostly blocking: three of the next five moves exist only to stop the other family reaching three.

Move seven leaves the teeth two ways to finish. The clusters can only block one of them, so the last empty pocket decides the game before anyone reaches for it.

Nine pieces, one line across the front row. Whoever moves first gets 5 pieces to the other side's 4 — swap who opens, and the advantage swaps with it.

Two shapes, nine pieces

One tooth printed 5 times, one cluster printed 4 times. Nothing tells two pieces of a family apart except how far round they were turned going in — and since the foot is a plain disc, that angle is yours.

Close view of one purple tooth seated in a pocket, its disc foot standing proud of the board, with empty pockets alongside.
Tooth — 5 of them. A stubby faceted column under a blunt point, flat-sided enough that it reads the same from every chair at the table.
Close view of one mint-green cluster in the centre pocket, flat plates set at angles, with a purple tooth behind it.
Cluster — 4 of them. Flat plates jammed at angles, so it throws highlights where the tooth stays calm. Same foot, same 26 mm of height.

It drops in at any angle

Every piece stands on the same disc. The pocket under it is a plain circle, so there is no orientation to find and no tab to line up — you hold a piece over a hole and let go.

The empty board from above: nine shallow circular pockets in three rows, inside an uneven faceted rind.
The board on its own: 9 pockets sunk into a flat, with the rind left faceted and uneven around them — 14 mm tall at its highest corner and level with a pocket floor at its lowest.
Section through one cell: a 26 mm tooth on a Ø28 mm foot, seated in a Ø30 mm pocket 2 mm deep, with 1 mm of clearance all round. Ø28 mm foot Ø30 mm pocket 2 mm deep 26 mm 1 mm clearance
Section through one cell, drawn from the model.

A Ø28 mm foot in a Ø30 mm pocket leaves 1 mm of clearance all round, which is enough that a piece seats straight off the plate with no fettling. The pocket is 2 mm deep and the foot 3 mm thick, so 1 mm of it stays above the rib — that ledge is what your fingernail catches when you take the piece out again.

What arrives

Printed parts
10 — the board and 9 pieces
Overall, pieces seated
5.5 × 5.1 × 1.3 in
Weight, everything
3.3 oz
On the plate
8.2 hours
Pockets
9 at Ø30 mm, 36 mm pitch
Pieces
5 teeth, 4 clusters, 26 mm tall

Every figure here was measured off the model this page is rendering. The board, both piece shapes and the 9 pockets are one CAD file, and the film above runs on it.