Qubic

Overview

Qubic is 3D tic-tac-toe played on a 4x4x4 grid of 64 positions arranged across 4 transparent levels. Two or three players alternate placing pegs, trying to form a straight line of 4. The game was originally published by Parker Brothers in 1953 (as a 3x3x3 version) and later as a 4x4x4 in 1965.

Components

Component	Quantity
Playing frame (4 levels, 4x4 grid each)	1
Pegs (2-3 colors)	64 total

Setup

1. Assemble the 4-level playing frame.
2. Each player takes pegs of their color.
3. Determine who goes first.

Turn Structure

Players alternate turns. On your turn, place one peg of your color in any vacant position on any level.

Actions

Place a Peg

Insert one of your pegs into any open hole on any of the 4 levels.

Scoring / Victory Conditions

The first player to place 4 pegs in a straight line wins. The line can be:

• Horizontal on any single level (rows or columns)
• Vertical through all 4 levels in the same position
• Diagonal on a single level
• 3D diagonal through multiple levels

There are 76 possible winning lines in a 4x4x4 grid.

If all 64 positions are filled with no winner, the game is a draw.

Special Rules & Edge Cases

• With 3 players, the first player to complete a line wins regardless of when in the rotation it occurs.
• Mathematical analysis has shown that with perfect play, the first player can always win the 4x4x4 version (solved game).
• The 3D nature makes it significantly harder to block opponents than in regular tic-tac-toe.

Player Reference

Win Condition	4 pegs in a straight line
Grid	4 x 4 x 4 (64 positions)
Winning lines	76 possible
Players	2-3