The unit cannot Declare Charges and cannot move normally (Advance, March, Reform) in the Movement Phase (which also means they cannot perform Magical Moves). The model loses Swiftstride (and can never gain it), but always charges, Flees, Pursues and Overruns the distance stated in brackets.
In the Movement Phase, at the end of step 2 of the the it with Random Movement moves using the rules for Pursuing units, except that they can freely choose which direction to rotate towards before rolling the Pursuit Distance, cannot move off the Board Edge and only take Dangerous Terrain Tests if they actually charge an enemy unit (they still test as normal when Fleeing, Pursuing a Broken enemy or Overrunning).
Whenever a unit with Random Movement needs a March Rate (e.g. when Post-Combat Reforming), use the potential maximum value of X as its March Rate.
Characters with Random Movement can only join units with Random Movement (by moving into contact with them during the Movement Phase or by being deployed inside), and units with Random Movement can only be joined by Characters with Random Movement. Units with Random Movement cannot enter Buildings. If a unit has several sets of Random Movement, use the one with the lowest average (in case of a tie, you may choose which version to use). A model with Random Movement cannot move in the same phase as it arrives on the Battlefield as Reinforcement (Dawn Assault) or Ambusher.