Unless somehow prevented (by a special rule or by their troop type, for example), most characters can join a friendly unit. A character can join a friendly unit:

• During deployment, by being placed with the unit.

• During the Remaining Moves subphase, by moving into base contact with a unit that is not engaged in combat or fleeing.

A unit cannot move after being joined by a character during the Remaining Moves sub-phase. However, the unit only counts as having moved if it did so before the character moved to join it.

Note that a unit can be joined by more than one character, but two characters cannot join one another to form an ad hoc unit.