How to play Skyline
Skyline is a logic puzzle about lines of sight. You fill a 4×4 grid with tower heights 1 to 4 so that every row and column uses each height exactly once, and the numbers around the edges tell you how many towers you can see looking inward from that edge. A taller tower hides every shorter tower behind it. Every puzzle has exactly one solution and is solvable by logic alone.
How to play
- Fill the 4×4 grid with heights 1 to 4 so every row and every column uses each height exactly once.
- The numbers around the edges count how many towers are visible looking inward from that edge.
- A taller tower hides shorter towers behind it. In a row reading 1, 2, 3, 4 you see four towers from the left but only one from the right, because the 4 hides the rest.
- Tap a cell then a number, or use the number pad. Arrow keys move, 1–4 place a height, Backspace clears, and Home and End jump to the first and last cell.
- Turn on Notes to pencil in candidates, Undo to step back, and Check to highlight rule conflicts — Check never tells you a cell’s correct value.
Tips & strategy
- Start with the extreme clues. A clue of 1 means the tallest tower sits right at that edge, and a clue of 4 fixes the entire line as 1, 2, 3, 4 ascending.
- A clue of 2 or 3 restricts where the tallest tower can go — work out the possibilities rather than guessing.
- Combine the visibility clues with the each-height-once rule. Neither solves the puzzle alone; together they usually pin a cell immediately.
- Use Notes for candidate heights the way you would in Sudoku, then eliminate them as lines resolve.
- Never guess. Every puzzle is logically solvable, so a dead end means a deduction was missed.
Accessibility
Heights are digits and the edge clues are numbers, so nothing depends on colour, and Check highlights conflicts as text you can read.