Quantum tic-tac-toe — marks in two places at once
Each move puts your mark in two squares at once, and only later does it settle in one. When the marks form a loop, the other player chooses how it collapses. Tic-tac-toe becomes a game of decisions you don't control.
From Quantum tic-tac-toe, by Allan Goff.
What it shows a designer
Each move is uncertain until a later moment decides it, and the decision is handed to the opponent. It shows how a game can be built to teach an idea from science, with delayed effects as its main mechanism.
Credits
- Made by
- Allan Goff, 2002, made to teach quantum physics
- Sources
- www.cel.edu/Quantum/Tic-Tac-Toe/
doi.org/10.1119/1.2213635
What you need
- paper with a 3 by 3 grid, squares numbered 1 to 9
- a pen
How to play
- A move. X goes first. On move 1 write X1 small in two different empty squares; on move 2, O writes O2 in two squares; and so on. A square can hold several small marks.
- Loops. Think of each move as a line between its two squares. When a move closes a loop of these lines, the loop must collapse.
- Collapse. The player who did not close the loop picks one move in the loop and chooses which of its two squares it settles in. That fixes the others: each move in the loop, and any move tied to it, settles in its other square. Settled marks are written large and never move.
- Last square. When only one empty square is left, the last move puts both halves in it.
- Win. Three settled marks of yours in a line wins. If both players get a line in the same collapse, the line whose highest move number is lower scores 1 and the other 1/2. A full board with no line is a draw.
After playing, talk about
- When did you place a mark to force a loop?
- How did it feel when the other player chose your collapse?
- Did the rules make sense of entanglement for you?
Its blocks
Download it as a design (.md)In boardgameBuilder, Open game puts its blocks on the canvas. Changed, the same file can come back here from Propose a game.