「よんろのご」は、囲碁界のエース・張 栩（ちょう う）棋士が考案した、囲碁のルールを使ったパズルです。盤を大きな木に、白黒の石を赤と青のりんごに変えて、頭を使いながら楽しく問題を解いていきます。
家族や友達と遊びながら問題を解くうちに、「石を取る」という囲碁の基本的なルールや論理的な思考を養うことができます。
Roughly translated from the back of the box:
"4 by 4 Go" is a puzzle game designed by pro Go player Chang Hsu (AKA Cho U 9 dan) for his four-year-old daughter, which is based on the rules of Go. The name comes from there being 4 lines to play on, each line being called "RO" (1ro, 2ro, 3ro, etc) and "YON" meaning the number four.
Instead of the black and white stones common to Go, the game uses red and green discs resembling apples and the board has been made to look like a tree. Included is a booklet of puzzles questions for children to think about and arrange on the board to try solving with friends and family.
Once the first step of basic challenges has been completed, a 2 player Go-like game called "Stone Capture" (ishi o toru) can be played. [Players take turns placing apples (stones), capturing each others stones until either the opponent has no place to play or the board is dominated by one color.]
The box set includes:
15 Red Apples
15 Green Apples
Question Booklet
4x4 Go Board