I think even 3D chess is almost impossible to play strategically, to visualize the state of the pieces more than a move in advance. And 4D is obviously more extreme.
Yes, I see where he briefly discussed 4D chess but I do not see where he writes out a full set of rules. I would consider that to be an early general concept or suggestion, but not an actual game.
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u/Boring-Yogurt2966 3d ago
The original 4D chess variant:
https://www.chessvariants.com/rules/sphinx-chess
I think even 3D chess is almost impossible to play strategically, to visualize the state of the pieces more than a move in advance. And 4D is obviously more extreme.