Linnaeus

About Linnaeus

Linnaeus, named after the Swedish naturalist who founded modern biological classification, turns taxonomy into a quick daily round. The day's species appears with a photograph and its common name, the Monarch Butterfly on one October day, and below it the first fork of the tree of life: Eukaryota or Archaea. You pick a branch, and the next fork opens, level by level, six levels in all, until the species sits where it belongs.

Each choice has a ten-second timer. Answering fast and keeping a streak of correct choices earns bonus points, and a clue is available at a cost of a few points. The short timer is deliberate: its maker, a philosopher of biology, wanted to keep people from looking the groups up while they play.

The same species goes to everyone each day, and results go on daily and monthly leaderboards. Earlier days can be played through Previous day and a list of previous puzzles. The interface is offered in more than one language. Ariel Jonathan Roffé built the game with Claude Code and launched it on Show HN in October 2026.

How to play Linnaeus

1. Open Linnaeus and press Play today's puzzle.
2. Look at the day's species and its photo.
3. At each fork, choose the branch of the tree of life the species belongs to within ten seconds.
4. Continue down all six levels, using a clue if you are stuck at a cost of points.
5. Finish fast and without mistakes for a higher score on the daily leaderboard.

Screenshots

Tips

• Settle the big splits quickly: almost every species you will see is a eukaryote.
• Answer quickly when you know, and save the clue for the deeper, finer levels.
• Play earlier days from the archive to learn how groups such as orders and families split.

Questions