no, because everyone's moving in x,y,x integer coordinates limited to the cube's dimension, max x,y,x = 1000 for example, and the server records the coordinates

no, because everyone's moving in x,y,x integer coordinates limited to the cube's dimension, max x,y,x = 1000 for example, and the server records the coordinates you'be moving along (0,0,1), (1,0,0), (2,0,0). when you move into a coordinate someone (or you) has been, its a collision. although you move 1 point at a time, the line thickness in the Ui may be more than 1 pixel, it's just on the UI level. you start on the usual plain: y | | *--> | z-------x y is the vertical coordinate and x is the horizontal. that's the plane your're seeing on your game client. if you're moving right along the x line, you're increasing the x coordinate (x,y, z) while the others are constant if you press 'D' or 'right', you "turn" the view on the y axis, and then the plane you're on becomes: y | | *--> | x-----z now, y is the (same) vertical but the horizontal has become z, you keep moving right but x value has fixed and now z is increasing. if you press up, you start increasing y, but x, and z are still fixed (since you havent moved on their axis) the server records the x,y,x coordinates you been through (for everyone) and when someone moves into a recorded coordinate, game over man.