Dealing with the randomness of physics

So I’m making this turn based multiplayer game that has physics, and what I wanted to do was just send RPC’s between the players when a player starts their turn (By moving etc.) that has the Vector3 of their desired movement.

The problem is, even if the objects every property is the same, and both CLIENT and SERVER are giving the same Vector3 for the AddForce Command… The actual path of movement is not the same (especially after collisions), so even though everything is the same between the two players, one cube will end up in a different place than the other.

SO, I set up an experiment where a cube is repeatedly spawned and given a set impulse force, and indeed this happens regardless, it’s just simply a property of the physics engine?

So then my question is, is it possible to mess with the physics in the game so that there is no randomness, so that if one object is given a velocity from a certain starting point, another object of those parameters will have the same path?

Thanks for your help, apologies if I rambled.

You’re looking for a deterministic physics simulation (that should help you Google it). While this is possible, it’s one of the more difficult things to do, and without replacing Unity’s physics simulation I don’t believe it’s possible. Especially when you get into networking, floating point implementations and such.

You can refer to this answer for some additional discussion on the topic: