Description: Normally, units must maintain a distance of more than 1" from Impassable Terrain and other units, both friends and enemies. However, during ongoing moves, the Unit Spacing requirement is temporarily lowered to 0.5", but 1" must be maintained at the end of the move (i.e. units are allowed to be within 1", but outside 0, 5" of other units and Impassable Terrain during a move, but they are not allowed: to come into base contact, overlap with their bases, nor to voluntarily end the move within 1" of either Impassable Terrain nor other units).
During moves where the owning player of the unit does not have full control of the unit, including Charge Moves, Failed Charge Moves, Flee Moves, and Pursue Moves, the unit is allowed to approach, and end the move, closer than 0.5" of units and Impassable Terrain, but it is not allowed to come into contact or overlap with their bases (except Charge Moves, which can move into contact with the target of the charge).
If a unit moves closer than 1" as a result of an uncontrolled move, such as during a Charge Move, the unit is allowed to end the move closer than 1" away and is allowed to stay within 1" until the point at which it is outside 1" again.
Units are only allowed to move into base contact with another unit during specific circumstances, the most common being a Charge Move, where units are allowed to move into contact with other units, except enemy units that were not the target of the charge. This includes uncontrolled move, such as when moving a random distance (e.g. models with Random Movement or when performing a Failed Charge Move). Unless explicitly noted, units are not allowed to move into base contact with other units, not even temporarily.
When units end up within 1" of each as a result of unintended circumstances, or uncontrolled moves, these units are allowed to remain within 1" until the units are separated by more than 1", at which point the normal Unit Spacing rules apply again. Removing a unit from the battlefield, such as during a Reform, does not count as moving the unit farther away for this purpose, unless the unit is actually placed back further away than 1".