DWG-100
The tool wall
Eight puzzle types, 300 numbered sheets, and a free game for each. Sheets are grouped by difficulty, and every one of them has a single solution.
Sudoku
Nine rows, nine columns, nine boxes and one way to fill them. Every grid here is graded by the hardest technique it needs, so “hard” always means the same thing.
Killer Sudoku
A sudoku grid with no digits printed at all. Dashed cages tell you what their cells add up to — and that turns out to be plenty.
Nonogram
Numbers along the edges describe a picture, and logic turns them into one. Every grid here can be solved line by line without guessing.
Kakuro
A crossword built from numbers. Every run of white cells has a target sum, and the crossing runs keep each other honest.
Binary
Two symbols, three rules, one solution. No arithmetic at all — just patterns and counting.
Bridges
Every island tells you how many bridges it needs. Build them without crossings and make sure the whole archipelago hangs together.
Skyscrapers
A Latin square seen from the street. The numbers around the edge count how many buildings are visible from that side.
Lights
Every tap flips a small cross of lamps. The goal is a dark board — and on every sheet here exactly one set of lamps gets you there.