Game rules
Every puzzle on Ozerlyn is solved with logic alone: no guessing and no arithmetic. Pick a game to read its rules, see a worked example and learn the first techniques that get you unstuck.
How to play Sudoku
Fill a 9×9 grid so that every row, column and 3×3 box contains the digits 1 to 9 exactly once.
Sudoku is a logic puzzle played on a 9×9 grid. Some cells already contain digits (the clues). Your job is to fill every empty cell with a digit from 1 to 9 so that each row, each column and each of the nine 3×3 boxes contains every digit exactly once. You never need to guess or do any arithmetic: the digits are just nine different symbols.
Read the rules →How to play Skyscrapers
Place buildings of different heights in a grid so that the number of buildings visible from each edge matches the clue.
Skyscrapers is a logic puzzle played on a square N×N grid, for example 4×4 or 5×5. Each cell holds a building with a height from 1 to N, and every row and column must contain each height exactly once. The numbers around the edge tell you how many buildings you can see when you look along that row or column from that side; taller buildings hide shorter ones behind them.
Read the rules →