SudoPalace supports iPhone and iPad running iOS / iPadOS 17.0 or later, with English and Simplified Chinese. Contact MichaelSilvesterCN+SudoPalace@gmail.com for help.

Levels and stars

Which levels are free and why is the next level locked

Each of the five difficulties has 100 levels, with its first 10 free. Within a difficulty, clear the previous level or fill its answers to skip it before the next level opens.

From level 11 onward, also unlock the level with diamonds or hold active SudoPalace Pro membership. Pro removes the diamond cost but retains sequential progression. Individual unlocks cost 1 diamond for Easy or Medium, 2 for Hard or Expert, and 3 for Master.

How do I earn three stars

Finish with zero recorded mistakes, no Hint or Fill Cell use, and within the difficulty’s target time: 5 minutes for Easy, 8 for Medium, 13 for Hard, 20 for Expert, and 30 for Master.

Notes and Undo do not themselves disqualify three stars, but Undo does not reduce recorded mistakes. Three mistakes cause failure. Once per game, spend 1 diamond to revive: this resets mistakes and the timer, clears incorrect entries, and retains other progress. Stars then use the new timer and mistake count. Three stars remain possible if you use no Hint or Fill Cell and finish within the target time.

Why did replaying not award more rewards

Level coins are awarded on the first clear. Improving your star rating later awards only the difference; an unchanged rating awards nothing more. Each level awards diamonds only for its first three-star clear. An extra bonus applies to three stars on the first attempt; restarting cannot recover a first attempt already used.

Daily Challenge rewards are awarded only on the first clear that day. Replays give no further rewards. Filling answers to skip a level gives no stars, coins, or diamonds. You may replay a skipped level later.

Hint, Notes, and tutorials

What is the difference between Hint and Fill Cell

Hint costs 25 coins, directly fills a step found by the app, and displays an explanation. It corrects an existing wrong entry first. If the built-in basic hint techniques cannot explain the position, it provides a cell’s answer directly.

Fill Cell costs 1 diamond and fills the correct answer into the currently selected editable cell. Pro members pay the same tool costs.

Why can I not erase a number and why did Notes disappear

Given numbers and correctly entered numbers cannot be edited or erased directly. Undo can reverse the relevant historical move. In Notes mode, number buttons add or remove candidates. Notes mode starts off each time you enter or restart a game.

With Auto-Remove Notes enabled, a correct entry removes that number from Notes in the same row, column, and box. Turn this off in Settings if preferred.

Where can I learn Sudoku techniques

Open Technique Tutorials from the home screen. All eight lessons are free and include an introduction, step-by-step demonstration, and interactive practice. They cover rules, Naked and Hidden Singles, Locked Candidates, pairs, X-Wing, and XY-Wing. Completing lessons does not award coins or diamonds.

Daily Challenge and saved games

Why does Daily Challenge have a different difficulty than I expected

The difficulty is chosen between Easy and the highest difficulty you have cleared normally. Skipped levels do not increase this range. If you have no normal clears, the challenge is Easy. The day’s difficulty is fixed when you first open it; later clears at higher difficulties do not change that day’s puzzle.

How do I resume a game and why does backgrounding pause it

The app saves after moves and at regular intervals. Resume an unfinished board through Continue Game on the home screen or its level entry. Backgrounding pauses the game automatically. The timer stops while paused and the board is obscured.

Progress and currency stay on this device and do not synchronize across devices. Contact support before deleting the app to troubleshoot. There is currently no cloud save or saved-game import or export. Restore Purchases cannot recover this data after the app is deleted.

Membership and purchases

What does Pro include and why can I not claim my daily gift

Pro offers weekly, monthly, and annual subscriptions or a lifetime one-time purchase. It removes diamond unlock costs for all 500 levels and provides a daily member gift. Sequential progression still applies, and Hint, Fill Cell, revival, and skipping retain their currency costs.

Member Daily Gift on the home screen includes coins and diamonds; quantities are shown in the app. Claim it manually once per day. Unclaimed gifts do not accumulate. Connect to the internet, confirm your membership is active, and allow the app to verify Apple entitlements before retrying. Offline cached membership cannot claim a gift.

I paid but membership is inactive or currency is missing

• Check internet access and that the App Store uses the original purchasing Apple Account.
• Check Apple purchase history for completed, pending approval, or canceled transactions. Pending approval is not a completed purchase.
• For missing membership, choose Restore Purchases on the membership page or in Shop to restore active subscriptions or lifetime access.
• For missing coins or diamonds, keep the app installed and reopen it online so unfinished transactions can be processed. If they remain missing, contact support with the product name, purchase time, and necessary order information.

Coins and diamonds are consumable purchases. Balances delivered by completed transactions cannot be reissued through Restore Purchases. Restoring membership also does not recover saved games or diamond unlock records. See Apple’s purchase restoration guidance.

How do I cancel a subscription or request a refund

Open the membership page from the membership card in Settings and choose Manage Subscription, or use system Settings > Apple Account > Subscriptions. Deleting the app does not cancel a subscription. Lifetime access does not renew automatically. See Apple’s cancellation instructions.

Apple handles refunds. See Apple’s refund support. For a missing purchase, keep the app installed and contact support to troubleshoot first.

Language, appearance, and feedback

Change Language and Dark Mode under Settings > System. Language supports System, 简体中文, and English. The game interface updates immediately; some system interfaces may update after the next launch.

When reporting an issue, name SudoPalace and include the app version, device model, operating system version, steps, and error message. For game issues, add the difficulty, level number, whether it was Daily Challenge, and a screenshot. For purchase issues, provide the membership or currency product and purchase time. Redact unrelated personal information and never send account passwords or complete payment details.

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