Tic-Tac-Toe
Classic X's and O's — or the Sum 15 variant
About this game
Tic-Tac-Toe is a classic almost everyone already knows, so there's no learning curve to get started — and it still has real strategy: predicting the opponent's move and blocking in time.
Beyond the traditional X and O, DIVILLI also offers the "Sum 15" variant: the same nine spaces get numbers from 1 to 9, and whoever collects three numbers that add up to 15 wins — it's the same game underneath, just dressed differently, and a light way to practice mental math.
FAQ
Is the Sum 15 variant a different game from Tic-Tac-Toe?
No — it's the same game underneath: the numbers are arranged so that forming a line of three is always the same as adding up to 15 (a magic square). Only how the board is shown changes.
Is there a strategy to never lose at Tic-Tac-Toe?
Yes — always playing the best possible response, Tic-Tac-Toe never has to end in a loss, only a win or a draw. It's a good game for thinking a few moves ahead.