A 5 × 5 Shikaku has just 25 cells to carve into rectangles, so every clue does a lot of work: a 5 can only be a 1×5 strip, and one placed rectangle often forces the rest of the board. That makes this the best size for learning to read clues — you can see the whole grid at once and check every option in your head.
Don't mistake small for trivial, though. Our 5 × 5 hard boards use fewer, larger clues placed mid-rectangle, so two or three candidates stay open until you find the cell that only one rectangle can reach.
New to the rules? Start with the how-to-play guide, warm up on a few easy puzzles, or jump into today's daily Shikaku.