How to play Cyberdoku

Cyberdoku is a free block puzzle you play right in your browser — no download and no sign-up required. It blends the grid of sudoku with the satisfying block-placement of games like Tetris and Blockudoku. The goal is simple to learn but hard to master: keep the board clear for as long as you can and build the highest score you can.

The board

You play on a 9×9 grid, divided into nine 3×3 boxes — just like a sudoku board. Every cell starts empty, and your job is to fill cells in ways that complete full lines and boxes so they clear away.

Your pieces

• You're given three pieces at a time, shown below the board.
• Pieces come in different shapes — single blocks, lines, squares, L-shapes and more.
• Pieces can't be rotated. You place them exactly as they appear, so where each one goes takes a little planning.
• Once you've placed all three, a fresh set of three appears.

Placing a piece

Drag a piece onto any empty space it fits. As you drag, the board shows a live preview of where the piece will land, and highlights any line or box your drop would complete — so you can line up big clears before you let go. A piece can only be placed where all of its blocks land on empty cells.

Clearing lines and boxes

You free up space by completely filling a line or a box. Fill an entire row, an entire column, or a full 3×3 box, and those cells clear away, making room for more pieces. A single well-placed piece can complete more than one of these at once — and clearing several at the same time is where the big scores come from.

Scoring

• You earn a point for every block in a piece you place.
• Each row, column, or box you clear is worth a large bonus.
• Clearing more than one line or box with a single placement earns an extra multi-clear bonus.
• Clearing on back-to-back placements builds a streak — each consecutive clear stacks a growing bonus on top.

When the game ends

The game ends when none of your three current pieces can be placed anywhere on the board. In classic mode a fresh set is always chosen so at least one piece fits while the board still has room — so a game over means you're genuinely out of moves with the pieces in front of you.

Game modes

Classic is the endless mode above. Daily Challenge gives every player the same sequence of pieces each day — three attempts, best score counts, resets at midnight UTC. VS duels let you challenge a friend to the same seeded pieces and compare scores. See the FAQ for more on each, and Strategy & Tips to start climbing the leaderboards.