Cross a pond of lily pads that sink behind every step, and reach goose on the far side.
Why duk.
A quiet puzzle that respects your attention
No timer counting down, no lives to run out, no advertisement between attempts. Just a pond, a route to find, and as long as you want to find it.
Every puzzle is solvable
Each pond is checked to have at least one winning route before it ever reaches you. The challenge is finding the path, never wondering whether one exists.
No ads, no accounts
Nothing to sign up for and nothing to dismiss. duk. plays fully offline, never connects to a server, and collects no data about you whatsoever.
Eighty ponds, plus a daily
A journey through eighty lily ponds of hand-checked puzzles, and a fresh puzzle every day if you just want one quiet thing to solve.
The rules
Learn it in about a minute
The goal: sink every lily pad, then land on goose.
Every lily shows a number, and that is exactly how far a move travels. Leave a lily and it sinks for good, so the pond shrinks with every move you make. The edge wraps, and goose can only be landed on with the final step.
Questions
Quick FAQ
Where can I get duk.?
duk. is in a public TestFlight beta and has not been released on the App Store yet. Email support@betulanoir.com and we will send you the TestFlight link.
Is my progress saved?
Yes. Progress is stored on your device and survives closing and reopening the app. Deleting the app erases it.
Does duk. need an internet connection?
No. duk. works fully offline and never connects to a server, including for the daily puzzle.
Does duk. collect any data?
No. No accounts, no analytics, no advertising, no tracking of any kind. See the privacy policy for the detail.
Is there a timer or a lives system?
Neither. Nothing counts down and nothing runs out. If you strand yourself, you simply restart the pond.
Who makes duk.?
Betula Noir LLC, an independent studio in Austin, Texas.
Try it
duk. is in public beta on TestFlight while we finish it. Ask and we will send you in.
About duk.
duk. is a single-player logic puzzle for iPhone, made by Betula Noir LLC in Austin, Texas. You play a small duck crossing a pond of lily pads toward goose, a friend waiting on the far side. The catch is that every lily you leave sinks behind you, so the pond you are standing in shrinks with every move you make. One careless route leaves you stranded on an island of your own making.
It belongs to the family of puzzles where the board changes as you solve it, closer to a sliding-tile or path-tracing puzzle than to a number game. Where sudoku asks you to deduce a fixed answer, duk. asks you to plan a sequence: not just where to go next, but what going there destroys. That single rule, that leaving a pad sinks it, is enough to generate puzzles that stay interesting for eighty ponds.
How a puzzle works
Each lily pad carries a number, and that number is exactly how many pads a move travels, one step at a time in the four compass directions. Paths may bend mid-move but may never cross themselves, and the starting pad counts as the first step. Pads you have left are gone, and so are the gaps in the pond, which means the board grows more constrained the further in you get. The pond edge wraps: step off one side and you reappear on the other side of that row or column, which is often the move people miss.
Goose is the finish. You may paddle across goose in the middle of a move, but you may only come to rest on it with the final step of the whole puzzle, once every other lily has sunk. A full solution therefore has to account for every pad on the board, in an order that never traps you.
Playing without pressure
There is no clock, no lives system, no streak to protect, and no advertisement waiting between attempts. Stranding yourself is not a failure state so much as information: you restart the pond knowing something about it you did not know before. The daily puzzle exists for people who want one small thing to think about each morning, and the eighty ponds are there when you want to keep going.
Privacy and offline play
duk. has no accounts, no login, and no network calls at all. It collects no personal data, no device identifiers, no location, and no analytics, and it works on a plane or in a basement exactly as it does anywhere else. Your progress and statistics live on your device using Apple's on-device storage and are never transmitted anywhere. The full detail is in the privacy policy.
Getting help
The support page covers the rules, saved progress, and offline behaviour, and the how to play guide works through the rules with examples. Anything else, email support@betulanoir.com and a person will answer.