Tic Tac Toe in C#

Overview

This project is a console-based Tic-Tac-Toe game in C#. I wanted to build a computer opponent that would not lose, so I worked through the possible opening moves and follow-up positions on a 3×3 board, then encoded the responses directly in the program.

A strategy written as cases

Instead of using a general-purpose game-tree search, the opponent's strategy is a set of explicit if/else branches. The branches account for the player's opening and subsequent board positions, choosing from the available moves accordingly. For example, when the player opens in a corner, the program responds in the center:

if (AngkaAksiUser == 1 || AngkaAksiUser == 3 || AngkaAksiUser == 7 || AngkaAksiUser == 9)
{
    AksiKe++;
    AngkaAksiKomputer = CariAksiKomputer(SudahBerisi, 5);
    SudahBerisi.Add(AngkaAksiKomputer);
    Board = LakukanAksi(Board, AngkaAksiKomputer, 2);
}

Later turns use the current board to select the next move and check whether the game has ended:

AngkaAksiKomputer = CariAksiKomputer(
    SudahBerisi,
    OtomaticNyerangBlokir(Board, SudahBerisi)
);
SudahBerisi.Add(AngkaAksiKomputer);
Board = LakukanAksi(Board, AngkaAksiKomputer, 2);

if (CekMenang(Board) > -1)
{
    break;
}

This approach made the full set of cases visible in code, but also meant writing and checking many branches by hand. It was a practical way for me to explore game logic and translate the outcomes I analyzed into a working opponent.

I built the project while I was in high school, as I was learning about game development and wanted to experiment with how logic could drive a game-playing program.