Stake hexes and link all three sides of the triangle with a single unbroken chain before your rival does.
Players take turns placing a stone on any empty hexagon of a triangular board. You win the instant your stones form one continuous chain that touches all three edges. Thanks to the board's geometry, the game can never end in a draw.
Y was first described by the mathematician John Milnor in the early 1950s, then independently invented in 1953 by Craige Schensted and Charles Titus — the kind of double origin that tends to happen when a game is really a theorem waiting to be noticed.
It belongs to the connection family alongside Hex, TwixT and Havannah. The board is a triangle of hexagonal cells, and the object is to build a single connected chain touching all three sides.
Its elegance is that it generalises its relatives: Hex can be understood as a special case of Y. Like Hex it also cannot end in a draw — a completed board always contains exactly one winning connection — which is why it keeps drawing mathematicians back to it.
Y is an original free browser version of the classic hex-board connection game, a pure abstract strategy contest where careful chain-building always decides the result. No download required.