Picross 3D

Picross 3D extends the classic nonogram (Picross) concept from two dimensions into three. Instead of filling cells on a flat grid, the player starts with a rectangular block of cubes and must chisel away cubes to reveal a 3D object hidden inside. Each row, column, and depth line is labeled with a number indicating how many cubes should remain in that line, and special markings indicate whether the remaining cubes form one continuous group or are split into separate groups. The result is a recognizable 3D model — an animal, object, or shape — making the puzzle both a logic exercise and a sculpting experience.

Rules

1. You start with a solid rectangular block made of small cubes (e.g., 5x5x5).
2. Numbers on the edges indicate how many cubes in that row/column/depth must remain.
3. Number markings indicate grouping:

• Plain number: All remaining cubes in that line form a single connected group.
• Circled number: The remaining cubes are split into exactly two separate groups.
• Squared number: The remaining cubes are split into three or more groups.

1. Remove (chisel away) cubes that shouldn't be part of the final shape.
2. A cube is either kept or removed — there is no partial state.
3. The puzzle has a unique solution that forms a recognizable 3D shape.

Strategies

• Zero Lines: If a line is marked with 0, all cubes in that line must be removed.
• Full Lines: If a line's number equals the total number of cubes in that line, all cubes are kept.
• Plain Number Placement: A plain (ungrouped) number means one continuous block. If the number is close to the line length, you can determine which cubes must be kept by overlap logic (same as standard nonograms).
• Circled Numbers: Two groups means at least one gap. A circled "2" in a 5-cube line means two groups of cubes with a gap — possibilities are limited.
• Slice Analysis: View the block from different angles (top, front, side) to apply 2D nonogram logic to each slice.
• Cross-Reference Three Axes: Each cube belongs to three lines (row, column, depth). Constraints from all three must be satisfied simultaneously, which narrows possibilities quickly.
• Edge and Corner Cubes: Cubes on the edges and corners of the block are constrained by fewer lines but can be easier to determine when their lines have strong constraints.

Picross 3D was developed by HAL Laboratory and published by Nintendo for the Nintendo DS in 2009 (Japan) and 2010 (worldwide). The game was conceived as a natural evolution of the hugely successful "Picross DS" (2007) and the earlier "Mario's Picross" games for the Game Boy.

The concept of extending picture logic puzzles into three dimensions had been explored mathematically before the game's release, but Nintendo and HAL Laboratory were the first to create a commercially successful implementation. The key innovation was the user interface — using the DS stylus to rotate, zoom, and chisel a 3D block felt intuitive and satisfying, transforming what could have been a confusing spatial challenge into an accessible puzzle experience.

The game received critical acclaim, with reviewers praising its elegant tutorial system, the satisfaction of seeing 3D shapes emerge from solved puzzles, and the sheer volume of content (over 350 puzzles). A sequel, "Picross 3D: Round 2," was released for the Nintendo 3DS in 2015 (Japan) and 2016 (worldwide), adding color to the mix — cubes could be painted in two colors, adding another layer of deduction.

While Picross 3D remains primarily associated with Nintendo's handheld platforms, the concept has inspired independent developers to create similar 3D nonogram games for PC, mobile, and VR. The puzzle type appears under various names including "3D Griddlers," "3D Nonograms," and "Voxel puzzles." The format is particularly well-suited to digital platforms because physical rotation and layer-by-layer inspection would be impractical with pencil and paper.