The 196-year word puzzle
I built a daily word puzzle called Tessera. This week I asked it a question I thought had a boring answer: how long until we run out of new puzzles?
It's not boring.
Tessera is a 4×4 grid where you swap letter tiles until every row spells a word. The gold grids are constrained: not any 16 letters, but ones where all four rows AND all four columns spell real words simultaneously.
Sounds like a constraint that should crush the puzzle space. It does the opposite.
Start with the wordlist: 2,000 four-letter solution words. Pick four as rows in order and you have 2,000^4 = 16 trillion candidate grids. Most are nonsense: stack four random words and the four columns you read down through them spell garbage.
Now layer the column rule. Every column also has to be one of the 2,000 solution words. The survival rate is brutal. Out of 16 trillion candidates, roughly 71,000 produce a valid grid. About 1 in 225 million.
>71,000 sounds small until you compare it to "one per day": 196 years before the well runs dry. Tessera launched in April 2026. The math says we don't have to expand the list or start repeating until 2222.
The first repeat comes sooner of course. Birthday paradox math says day 315 is when the first duplicate becomes likely. After 5 years of daily puzzles you'd expect ~30 repeats out of 1,825 (1.6%). After 30 years, ~800 out of 11,000 (~7%). The space is so large that repeats stay invisible for the lifetime of the game.
For comparison: Wordle uses a curated list of ~2,300 solution words. They launched in October 2021. Sometime around 2028 they have to expand the list or start repeating. That's not a dig, it's just the math of "one word per day from a fixed list."
Tessera goes about 30× further on a wordlist of similar size. The reason is the cross-constraint. A grid where all eight words (4 rows, 4 columns) interlock is a much richer combinatorial object than a single hidden word. Adding the column rule didn't shrink the space, it multiplied it.
You set out to ship a small game. You run the back-of-envelope on its shelf life. The answer comes back: your grandchildren can play this.
Try it: https://www.tesserapuzzle.com