oxo3d - 3d noughts and crosses / tic-tac-toe

Oxo 3D is a 3 dimensional (4x4x4) noughts-and-crosses / tic-tac-toe game for pico-8. This is a game with considerably more strategy than the traditional 3x3 version.

Quick start

You're O and you have to get 4 in a row. The board is a cube viewed in slices. Imagine the 4 slices piled on top of each other.

Use the arrow keys to move the highlight and press Z to place a piece.

Use X to view the cube in different orientations.

Use Enter to view the menu to change level.

Watch out for tricky diagonal lines!

Good luck!

How to play 3D Noughts-and-Crosses

Each group of 4x4 positions represents one plane on the cube.

On each layer there are 10 possible winning lines, 4 horizontal, 4 vertical and two diagonal.

However lines may run from layer to layer also.

There are 76 lines in total possible, these are 4x4 = north-south lines, 16 east-west lines, 16 vertical lines, 2x4x3 = 24 diagonal lines from one edge to another, and 4 diagonal lines from corner to corner.

Levels

There are 3 carefully graduated levels which you change with the cartridge menu (Enter).

Easy
Medium
Hard

The levels get increasingly hard. Easy and Medium use the same simple heuristic player, but Easy makes random mistakes. Hard uses a two level lookahead player - watch out is is very sneaky.

History

Written in ZX81 BASIC (1983)
Converted to QL BASIC(1985)
Converted to BBC Basic (1985)
Converted to Psion 3a OPL (1994)
Converted to C (1996)
Converted to Perl (2000)
Converted to Python (2004)
Converted to LUA and pico-8 (2019)

I used to play this game with my father when I was a boy. We always used to play on squared paper while sitting round the kitchen table. When I was old enough (and the home computer had been invented) this inspired me to write a computer player for the game.

The very first version of this game was written in 1983 on a Sinclair ZX81 in BASIC. It used to take 60 seconds to think of a move, and it used to beat the author nearly all of the time.

This pico-8 version is a pretty faithful port of the original ZX81 game though I think the original program only had the equivalent of Medium difficulty.

I wrote this as a first step towards getting my son interested in pico-8 programming - I thought I'd better learn how first!