Does the stack has to move on ?

When a stack enters an empty tile or a tile that contains only stacks of the moving player, than the stack must try to move on. 

Exception: if  the tile does have a campfire symbol the player may choose to stop moving this stack.

Designer notes.
This rule is just part of the random movement and would not be needed if all stacks would move D6 tiles instead of doing command tests. The campfire is just an gimmic that gives the players something more to consider.