In Shikaku every region is a rectangle containing exactly one number. In Fillomino regions can be any connected shape, a region can contain several copies of its number or none at all, and two regions of the same size may not touch along an edge.
Side by side
| Shikaku | Fillomino | |
|---|---|---|
| Region shape | Rectangles only | Any connected shape (polyomino) |
| Numbers per region | Exactly one | Zero, one or several (all equal) |
| You write | Rectangle outlines | A number in every cell |
| Extra rule | — | Same-size regions may not share an edge |
| Publisher | Nikoli | Nikoli |
In detail
Fillomino’s freedom of shape makes each region harder to pin down, while its “no same-size neighbours” rule adds a new kind of deduction. Shikaku’s rectangle restriction makes options easy to list, so its logic is more about blocking and reachability.
Shikaku skills transfer well: thinking in areas, listing options and spotting cells only one region can reach all help in Fillomino.
Which should you play?
Start with Shikaku if you are new to area puzzles — its options are easier to see. Try Fillomino when you want more freedom and a second kind of constraint.
Play Shikaku now
Six sizes, three levels, every puzzle with a unique solution.
Questions
Is Fillomino like Shikaku?
Yes — in both, numbers give region sizes. Fillomino allows any shape and has a rule against equal-sized neighbours; Shikaku requires rectangles with exactly one number each.
Which is easier, Shikaku or Fillomino?
Most people find Shikaku easier to learn because rectangles have far fewer possible shapes.