Frequently asked questions
Is Rocksled Sudoku free?
Yes. The game is free to play. If it shows advertising or a sponsor message, it is kept to unobtrusive banners: never a pop-up, and never a video or full-screen ad between puzzles.
Do I need an account to play?
No. You can play without an account, and your games, settings and statistics stay on your own device. An account is optional.
What does the game do with my data?
It collects as little as it can and never sells it. Without an account, what you do stays on your device. The privacy policy lists exactly what is kept and for how long.
How are the difficulty levels decided?
Each puzzle is solved by a program that uses human techniques and counts every step. A technique that is harder to spot scores more points, and the total decides the level, from Easy to Expert. A puzzle that needs a rare technique is never rated below that technique’s level. Every puzzle has a page that shows the working.
What are the hints, and do they just give the answer?
A hint starts with a nudge about where to look. Ask for more and it explains the technique and why it works, marking the cells involved on the board. You can switch hints off in Settings.
Does it work offline?
Yes. Once the game has loaded, you can install it like an app and keep playing without a connection.
What is the daily puzzle?
It is one puzzle each day, the same for everyone. It starts at midnight in your own time zone.
What is the difference between cell first and number first?
Cell first means you tap a cell and then tap a number. Number first means you tap a number and then tap as many cells as you like to place it, which is handy when you want the same digit in many places.
Can I use pencil notes?
Yes. Notes mode writes small candidates in a cell. If you prefer, you can switch on corner and center marks in Settings, which gives you two kinds of notes.
Can I play with one hand on a phone?
Yes. One Handed Play in Settings, on phones and tablets, puts the number pad at one edge of the screen with the other buttons beside it, for the hand you hold the phone with.
How many puzzles are there?
More than 3,000, across five levels, and the collection keeps growing.
More questions? Read how to play or about the game.