A model with the Hidden Special rule can choose to be deployed “Hidden”. If so, secretly note in which friendly (non-character) unit it is hiding in. This unit must already have been deployed, and must have the same Troop Type as the model with Hidden. Furthermore, the model must be allowed to join it normally. If the hiding model is a unit champion, it must hide in its own unit. While hidden, the model cannot be harmed or otherwise affected. Unless the unit that the character is hiding in
is fleeing, the model can be revealed at the start or end of any Player Turn or at the start of any Round of Combat that its unit is participating in. Place the model inside the unit as if it just joined the unit, placing it as far forward as possible (First in Rank), except that it cannot move other models with the First in Rank rule. Once revealed, the model functions as normal and this rule has no effect anymore. If the model is never removed during the game (for example, because its unit was destroyed), the hiding model counts as killed.