Mechanisms of interpenetration

Just confirming - If a unit which can be freely interpenetrated is at an angle to the unit which does the penetration then the interpenetrated unit moves to the rear of the interpenetrating unit - not its own rear.

So for example - if a unit of FL is in front of a unit of FP but at 90 degrees to its frontage - so forming a T shape.

The FP make a single move forward which places them about half way through the FL units position- the FL move sideways from their current position and are placed behind the FP unit. ( I think)

However, what if there were other units behind the FP - does the FL keep moving back through them and pop right out the back? Or does the presence of the other units prevent the interpenetration occurring?

Another one. Same situation - but the FP wants to move right through the FL's position and come out the other side. To get fully clear would take the FP 3 movement phases. So does the FP do his moves, and if he succeeds his discipline tests he is placed clear in front with the FL still in place? Or is the FL forced to move to the rear with the first movement phase?

Hope I have explained clearly enough. Let me know if I haven't.

Let's go easiest to hardest.

It is where the FP ends its move that decides on whether the FL displaces. If the FP in your example clears the FL in one activation then the FL does not displace.

The FL keeps displacing until there is enough space to be replaced.

I have to admit that even after playing hundreds of games of Impetus I still get caught on how units displace. The rule says behind the displacing unit so your example is probably correct although I suspect in our games we've moved the FL backwards as well. I hope Lorenzo in the 2nd edition puts lots of examples and pictures around this one.

Thanks. we struggle for consistency here too.

By "one activation" do you mean one movement phase, or multiple movement phases taken concurrently?

Multiple movement phases taken concurrently. In your example had the FP failed its DT after the second move the FL would have to displace. Note that if the reverse had occurred and the FL was trying to move through the FP and had ended its move on top of the FP the FL would displace back.