Warning — hard puzzles may require X-Wing, Y-Wing & Swordfish techniques. Not for beginners!
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Settings
Cursor type
Peer shading
Same-digit shading
Conflict checking
Timer
Solved!
Instructions
Tap
Selects a square — one at a time. Tapping away from the board deselects.
Double-tap
On a square down to a single candidate, enters that
digit. On one with several, turns on candidate editing,
so the digit pad pencils marks in instead — double-tap again to leave.
Triple-tap
Carries on from the double-tap: fills in every square
that is down to a single candidate, one at a time. Each digit entered can
narrow a neighbour to one candidate, so the board is checked again after
every placement and the run keeps going until no square has a lone
candidate left.
Long-press
Turns candidate editing on, the same as a double-tap on a square with several candidates.
Keyboard
1-9 enter a digit; 0, Backspace and Delete erase; arrow keys or WASD move.
Reset puzzle?
This will clear every digit and pencil mark you have entered, and restart the clock.
