Keystone - A balancing game. Easy to learn. Hard to master.

Intro

Keystone is a calm but surprisingly challenging balancing game for two players. Build a wall from small, asymmetric stones — each piece is different, every round plays out differently, and every move matters.

You can play together as a team, carefully building the tallest and most stable wall you can… or play against each other , taking turns and testing who has the steadier hands and the smarter strategy.

It may look simple at first, but the tension builds quickly: Do you start with large stones at the base? Offset pieces for stability? Take a risk to gain height?

And here’s the twist: every stone could be the „Keystone“ — the one critical piece that holds everything together… or decides the moment it all comes crashing down.

Best of all: Keystone is easy to print on almost any 3D printer , because it only needs a 18 × 18 cm build area.

With 42 unique designed stones and endless combinations, Keystone is easy to learn, but hard to master.

Rules

Goal: Build the tallest stable wall possible — without making it collapse .

Play against each other

- Pick your color. But: All 42 stones are shared.

- Players take turns placing one stone onto the wall. You may build a flat wall, a circle, whatever you want.

- You may rotate and adjust your stone — but you may only touch the wall during your turn .

- If the wall collapses, the round ends immediately.

- Now count only the stones that fell off the wall : For each fallen stone, check which color is facing up . Count how many Blue-up and how many Green-up . The color with the higher number wins the round.

Play together as a team

- Take turns placing one stone onto the wall.

- You may build a flat wall, a circle, whatever you want.

- After each turn, the wall must stand on its own.

- If the wall collapses , the game ends.

- Count the remaining pieces in your hand and try to beat yourself in the next round.

Why you'll love it?

- Deceptively simple, surprisingly challenging game

- Play together or compete

- Every game feels different thanks to 42 unique stones

- Compact & easy to print — fits on almost any printer ( 18 × 18 cm )

Recommended print settings

- Nozzle: 0.4

- Layers: 0.2

- Infill: 25%

- Perimeters: 3

- Seam: Rear

- Infill Speed: 240

- Add a color change at layer 13 and 49 for a three layer design OR add a color change at layer 31 for a two color design

- Optional: If you want the game to be a bit easier, add fuzzy skin in your slicer options. This will cause the stones to stick together a bit more.

- Material: I recommend to use PLA (see below) but other types of filament will work too.

Filament recommendation

I printed this model using Prusa Prusament and got great results. See below for my recommendations.

Prusament PLA Chalky Blue

Prusament PLA Pistachio Green