What


That would be incredibly interesting, even if I just watched.
Would you sit back and watch the others duke it out, or would you go head on and face the unknown?

Don't know. The squares are not squares for one thing, pawns are gonna get broadsided so they'd have to have new powers. Seems a bit unfair, 2 players could just gang up on the stronger player.
I guess it could be a little like the scene at the end of The Good The Bad And The Ugly. A tense 3-way shoot out.

I can see how they would move, right in the "front" of you the pieces would move either from the tip of the triangle, or the base. That would work, basically, the same with the bishops. The rook, if you followed the first part, would be easy to move, probably the easiest.

The closest red pawn in the pic, if it were to move 2 spaces forward then the white pawn on the left side wouldn't be able to move 2.
Maybe instead of going for the centre you have to try dominate your own flanks.
Would be interesting to see how a game of this pans out. Gives me a headache just looking at it.