Oxo3d

This is a suite of Go programs for playing and testing 3D noughts and crosses / tic tac toe.

Or try it in your terminal in old school ASCII:

go get -u github.com/ncw/oxo3d
oxo3d

+-------------+-------------+
| .  .  .  .  |  0  1  2  3 |
| .  .  .  .  |  4  5  6  7 |
| .  .  .  .  |  8  9 10 11 |
| .  .  .  .  | 12 13 14 15 |
+-------------+-------------+
| .  .  .  .  | 16 17 18 19 |
| .  .  .  .  | 20 21 22 23 |
| .  .  .  .  | 24 25 26 27 |
| .  .  .  X* | 28 29 30 31 |
+-------------+-------------+
| .  .  .  .  | 32 33 34 35 |
| .  .  .  .  | 36 37 38 39 |
| .  .  .  .  | 40 41 42 43 |
| .  .  .  .  | 44 45 46 47 |
+-------------+-------------+
| .  .  .  .  | 48 49 50 51 |
| .  .  .  .  | 52 53 54 55 |
| .  .  .  .  | 56 57 58 59 |
| .  .  .  .  | 60 61 62 63 |
Go (0..63) 

Playing the game

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

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.

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 ines from corner to corner.

Levels

There are 6 carefully graduated levels with interesting names.

The levels get increasingly hard. Easy and Simple use the same simple heuristic player, but Easy makes random mistakes. Sneaky uses a two level lookahead player. It is called Sneaky for good reason as you'll see when you play it. Relentless plays very slightly better than Sneaky but with a completely different style. Hard is exactly that and Very Hard plays so well that I haven't beaten it yet.

Level name	Internal name	Description	Rank
Easy	Heuristic0	1 level lookahead heuristic player with random errors	1
Simple	Heuristic1	1 level lookahead heuristic player	2
Sneaky	Heuristic2	2 level lookahead heuristic player	3
Relentless	AlphaBeta2	2 level lookahead minimax player	4
Hard	AlphaBeta3	3 level lookahead minimax player	5
Very Hard	AlphaBeta4	4 level lookahead minimax player	6

If you play 2,500 rounds of each one against the other this is what the scores look like. A Random player is included too as a control. There are some interesting reversals of form in the table

Player 1	Player 2	Wins	Draws	Losses	Player 1 time per go	Player 2 time per go
Heuristic0	Random	2500	0	0	182041 ns	3506 ns
Heuristic1	Random	2500	0	0	17193 ns	1502 ns
Heuristic2	Random	2500	0	0	24100 ns	789 ns
AlphaBeta1	Random	2500	0	0	18244 ns	1320 ns
AlphaBeta2	Random	2500	0	0	220337 ns	307 ns
AlphaBeta3	Random	2500	0	0	6296231 ns	318 ns
AlphaBeta4	Random	2500	0	0	88652221 ns	413 ns
Heuristic1	Heuristic0	2470	0	30	10722 ns	145330 ns
Heuristic2	Heuristic0	2274	22	204	17717 ns	120008 ns
AlphaBeta1	Heuristic0	2185	0	315	14914 ns	146380 ns
AlphaBeta2	Heuristic0	2465	1	34	248772 ns	51983 ns
AlphaBeta3	Heuristic0	2470	0	30	6134420 ns	19663 ns
AlphaBeta4	Heuristic0	2489	1	10	133985769 ns	15304 ns
Heuristic2	Heuristic1	1002	642	856	16801 ns	8780 ns
AlphaBeta1	Heuristic1	242	2	2256	15445 ns	10625 ns
AlphaBeta2	Heuristic1	1187	486	827	184999 ns	8261 ns
AlphaBeta3	Heuristic1	1470	124	906	4577929 ns	8403 ns
AlphaBeta4	Heuristic1	1775	216	509	93224450 ns	8681 ns
AlphaBeta1	Heuristic2	864	45	1591	13980 ns	20328 ns
AlphaBeta2	Heuristic2	1326	621	553	156175 ns	16215 ns
AlphaBeta3	Heuristic2	1848	81	571	4485952 ns	19077 ns
AlphaBeta4	Heuristic2	1599	660	241	49535585 ns	16807 ns
AlphaBeta2	AlphaBeta1	2220	1	279	234968 ns	13948 ns
AlphaBeta3	AlphaBeta1	2095	9	396	6054260 ns	13851 ns
AlphaBeta4	AlphaBeta1	2388	0	112	151574104 ns	14706 ns
AlphaBeta3	AlphaBeta2	1266	59	1175	4487537 ns	237976 ns
AlphaBeta4	AlphaBeta2	1319	193	988	86538385 ns	223163 ns
AlphaBeta4	AlphaBeta3	1740	85	675	82880581 ns	4723343 ns

...and here is the league table summary of the above

Player	Score	CPU Time
Random	-17500	72ms
Heuristic0	-11230	11.56s
AlphaBeta1	-4287	1.98s
Heuristic2	2035	4.54s
Heuristic1	4618	2.04s
AlphaBeta3	7506	15m51.07s
AlphaBeta2	7583	45.25s
AlphaBeta4	11275	5h19m56.46s

Interestingly the Heuristic1 player beats the Heuristic2 player overall, however you'll see in the detailed breakdown that the Heuristic2 player beats the Heuristic1 player.

History

• Converted to Web with Gopherjs (2018)
• Converted to Go (2013)
• Converted to Java on Android (2010)
• Converted to Python (2004)
• Converted to Perl (2000)
• Converted to C (1996)
• Converted to Psion 3a OPL (1994)
• Converted to BBC Basic (1985)
• Converted to QL BASIC(1985)
• Writen in ZX81 BASIC (1983)
• 35 Years in the Making!

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. It used the Heuristic1 player. However computing has moved on, and the current version plays at a much higher strength almost instantly. The author has improved too!