The monster order is written in chronological order of the creation of all monsters in a level, except ones on clone machines or on the lower layer. This can be automatically adjusted by a special menu in all level editors without having to erase and remake all monsters in the level.
All monsters move before Chip, but the monster ahead of the others in the monster order will move onto a space first if more than one is trying to step on the space, and the other monster(s) will treat it like any other obstacle. An example can be shown here:
In the given image, both monsters are attempting to move onto [1, 1] on the same turn. If the tank is ahead in the monster order, it will play L while the pink ball, with its north end blocked off, will reverse direction and play D. The tank will then die on the bomb, which allows the ball to play north and south without interference. If the tank is behind in the monster order, it will try to move L but fail, while the pink ball plays vertically continuously. When Chip decides to touch the blue button, the tank will reverse onto the force floor and head back west. If the ball is on [1, 2] moving north or at [1, 1], the tank is again blocked. If the ball is instead at [1, 3], the tank will move L, and act as an obstacle to the ball while still alive, which reverses D, then bounces up and down again.
When Chip's Challenge was first created, the editors did not have this knowledge, and therefore sometimes the clone machines and traps had the right controller/boss and sometimes they did not. Nowadays, level makers will either arrange the monsters in a different manner or add an extra monster stuck in an unconnected trap in order to avoid this. Some makers add another step; the boss/controller already exists, and Chip must create a new one or destroy the old one to get the trap or clone machine to clone/release in the desired direction, or to not clone/release at all.