Block their way
SolRush is a free 1v1 strategy game you play straight in the browser — the classic Quoridor, online. Get your pawn to the far side of the 9×9 board before your opponent does, and use your ten walls to make their path longer. A wall cannot be jumped, only walked around, and you may never block someone off completely. Play against real people, against a friend by room code, or against the AI. No download and no signup.