Lachaino is a deduction game for two players. Each player makes a chain of consecutive numbers that fills a square grid; for example, if 10x10 grids are used, each player fills a grid with the numbers 1-100 with each number adjacent to the previous one.
On a turn a player specifies a 2x2 section of the grid and the opposing player gives the product of the four numbers it contains, broken down into prime factors.
The object is to reconstruct the opponent's chain in the fewest number of guesses. If a player finds that one or both ends of the chain are ambiguous due to all four end numbers being in a 2x2 section, they may leave these undefined for a half-guess penalty each.
The game was first presented in Hopscotch #65 and then printed in World Game Review #8.
—user summary