Tridem
Rate itSlide three linked pieces onto their goals, under a rule that changes each weekday.
Every day: One numbered board a day (No. 279 on 6 October 2026), the same for everyone, with a movement rule that changes by weekday and a par number of moves. New puzzle: Once a day.
Tridem is a free daily sliding puzzle from Puzzlebyrinth. Three pieces, a circle, a ring and a diamond, move together with every arrow press, and you have to bring all three onto their dashed goal marks. Each weekday has its own twist, such as one piece moving left and right reversed, and each puzzle has a single optimal solution.
About Tridem
Tridem is the daily puzzle of Puzzlebyrinth, a site of reviews and essays about thinking games. Its idea is that three pieces slide as one: every move you make with the arrow keys or a swipe moves all three at once, and walls and blocks stop each piece separately. The goal is to land every piece on its own goal square at the same time.
The rule changes with the day of the week, building a small weekly arc. On a Mirror day, for example, only the diamond moves left and right reversed, so a move that brings two pieces closer can push the third away. Each puzzle has a difficulty rating in stars, a par for the number of moves, and a unique optimal solution that the engine checks.
You can undo, reset, ask for a hint or reveal the answer, and a daily leaderboard lists self-reported results. The date arrows let you go back through the archive, and the site says its puzzles run for two years, 728 in all, without looping. The page notes that the game's interface is in Japanese, though the English page shows the rules and labels in English.
It suits players who enjoy Sokoban-style puzzles and games like Stephen's Sausage Roll, in a form that takes a few minutes a day.
How to play Tridem
- Open Tridem and read today's rule, shown under the puzzle number.
- Press an arrow key, use WASD or swipe: all three pieces move at once in that direction, following the day's rule.
- Use walls and blocks to stop one piece while the others keep moving.
- Bring every piece onto its dashed goal mark, aiming to match par.
- Use Z to undo, R to reset or H for a hint, and the date arrows for past puzzles.
Screenshots
Tips
- Read the day's rule first: it changes which moves bring the pieces together.
- Look for a wall that can hold one piece in place while you line up the others.
- Count moves against par; if you go far over, reset and look for a shorter idea.
Questions
Does Tridem change every day?
Yes. It is updated daily, and the movement rule changes by weekday.
Can I play older Tridem puzzles?
Yes. Use the arrow next to the date to revisit past puzzles in the archive.
Does each Tridem puzzle have one answer?
Each puzzle has a unique optimal solution that the engine verifies.
Ratings and reviews
No ratings yet. Be the first to rate Tridem.
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