Ancient Origins
Games played on three-in-a-row boards can be traced back to ancient Egypt, where such game boards have been found on roofing tiles dating from around 1300 BCE.
Tic-Tac-Toe
You are Heads (H). The computer is Tails (T).
Your turn!
0Your Wins
0Comp Wins
0Draws
Coin Tic-Tac-Toe.
Heads vs Tails.
Take a break from deciding and play a classic game of Tic-Tac-Toe against the computer. Will Heads prevail over Tails?
About Tic-Tac-Toe
A simple yet deeply strategic game that has existed in various forms for millennia.
When two people play perfectly, Tic-Tac-Toe is a forced draw: neither side can create a winning line. That does not make every game a draw, though. Human decisions change the odds with every move, and a missed block or overlooked fork can turn a balanced position into a win. The first player has the advantage of moving first, but careful play can always secure at least a draw.
Roman Terni Lapilli
An early variation of tic-tac-toe was played in the Roman Empire, around the first century BC. It was called Terni Lapilli (three pebbles at a time) and instead of having any number of pieces, each player only had three, so they had to move them around to empty spaces to keep playing.
Perfect Play
Tic-tac-toe is a solved game, with a forced draw assuming best play from both players. However, our computer opponent occasionally makes sub-optimal moves to give you a fighting chance!
Strategic Depth
Despite its small 3x3 grid, tic-tac-toe offers genuine strategic choices. The opening move sets the tone: a corner forces the opponent to respond in the centre or risk a losing position, a centre opening is the most flexible but gives the opponent more room to manoeuvre, and an edge opening is generally considered the weakest start. Each position on the board carries different weight—corners participate in three possible lines (row, column, and diagonal), the centre in four, and edges in just two. This hierarchy of cell value creates a layered decision tree even in such a compact game. Modern analysis has shown that the game tree contains only 255,168 possible games (or 26,830 when symmetries are factored out), making it fully solvable. Yet the game remains enjoyable precisely because most players do not play perfectly; the tension comes from hoping your opponent will slip up on a critical move, turning an otherwise forced draw into a win.
Coins as Game Pieces
The connection between coins and games stretches back centuries. In the Roman Empire, small bronze and silver coins—particularly denarii and asses—were routinely used as counter pieces in board games. Archaeological finds from Roman Britain have uncovered game boards alongside sets of coins that were clearly being used as gaming tokens rather than currency. The practice continued through the medieval period, when European taverns and coffee houses featured games like nine-men's morris and early forms of chess, with coins standing in for pieces when dedicated sets were unavailable. By the 18th and 19th centuries, coin-based gambling had become widespread: penny farthings, slot machines, and various table games all relied on coins as both stakes and tokens. This dual role—currency and game piece—is what makes our coin-themed tic-tac-toe such a natural fit. The heads and tails faces of a coin are, in a sense, the oldest binary game markers in history, predating even the game itself.
The First-Move Advantage in Tic-Tac-Toe
Much like in chess, tic-tac-toe exhibits a strong "first-move advantage." The player who goes first (typically X) has the initiative and dictates the flow of the game. If the first player makes an optimal opening move—specifically playing in a corner—they guarantee at least a draw and force the second player into a highly precarious defensive position where a single mistake leads to an immediate loss.
Statistically, in a game played randomly (where players just choose empty squares without strategy), the first player wins 58.5% of the time, the second player wins 28.8% of the time, and 12.7% of games end in a draw. This statistical bias highlights why the initial determination of who goes first is so crucial.
Because the game strongly favors the first player, a fair method is required to decide who takes the initiative. This is precisely why a coin flip is often used before casual games. The 50/50 probability of the toss perfectly neutralizes the inherent imbalance of the game's mechanics, ensuring neither player is unfairly disadvantaged before the first X or O is even drawn.