# Shell Patterns — Binary rules Puzzle | Mathallery

Source: https://mathallery.com/games/shells/

[← All games](https://mathallery.com/games/)

# Shell Patterns

Binary rules · 30 levels

Eight little switches grow a seashell. Which ones?

## How to play

- Each new cell looks at the three cells above it (the row wraps around). The switch for that pattern says: pigment (dark) or plain.
- Tap a switch card to flip it. Your shell regrows row by row; red marks show where it differs from the target. 🔒 switches are given.
- Some targets are partly buried in sand, others only give a rule number: the 8 switches read as a binary number, 111 first.

Find a spot in the target where the three cells above are, say, ▪▫▪: the cell below tells you that switch.

[Open Shell Patterns](https://mathallery.com/#/play/shells/1)

Teeter, Tint and Echo Heist are free starters. Other games unlock through earned game choices or permanent packs. Your progress stays in the browser; optional sign-in saves it to your website account.