Some time ago I posted a question about a situation involving displacement. I sent the question to FFG as well, but it was not addressed in the latest rules update. The thread did not lead to a clear solution either, so I assume the situation is still some kind of grey area.
How would you resolve the following situation in a tournament as a judge:

Player A displaces miniatures of Player B's trooper unit without displacing the unit leader, but those miniatures cannot be placed in cohesion according to the rules on page 20. The unit leader is so tightly surrounded by impassable ground vehicles or creature troopers that it is not possible to perform a legal speed-1 move from the location of the trooper unit leader.

Last time there were some doubts that such a situation would actually occur in regular games. It is very possible to set up such a situation, though. It can be done with two or three ATRTs if a near enemy trooper unit has allready been activated, for example. Pivots and reverse moves make it even more practical. It is probably even easier with a combination of one ATRT and a unit of Tauntauns, because they have free pivot actions and a second miniature in the unit:

1. Player A moves an ATRT in base contact with a trooper unit leader so that the small base of the trooper unit is partially enclosed by the notch in the ATRTs base. The two units are in melee, but not engaged. Player B moves the remaining miniatures into base contact with the ATRT.

2. Later in the turn, player A displaces some of the miniatures of that trooper unit (but not the unit leader) with other vehicles/creature troopers in a way that the trooper unit leader is further enclosed by the bases of the vehicles/creature troopers.
Player A can for example do this by
a) using the notch of a second ATRT and put it into base contact with the trooper unit leader at the opposite side of his base or
b) use 2 more ATRTs to form a tight triangle around player B's trooper unit leader without displacing the trooper unit leader himself.
c) use a unit of Tauntauns and move both miniatures in base contact with player B's trooper unit leader without displacing the unit leader himself.

All these examples can lead to a situation where Player B cannot move a small base along the movement tool from the unit leader without passing parts of Player A's bases, which are impassable terrain for player B's Trooper units.

As a judge I would argue that you are not allowed to do that final move that makes cohesion impossible. Even if it is not your unit that is affected, you are actively causing the illegal situation. Problem solved

TL, DR: If you are causing an illegal situation with a move, then your move is illegal.

Just put the rest of the minis in base contact with the AT-RTs or Taun-Tauns as close as possible to the unit leader. Easy.

3 hours ago, colki said:

Just put the rest of the minis in base contact with the AT-RTs or Taun-Tauns as close as possible to the unit leader. Easy.

I don't understand. Isn't any arbitrary decision one might make when judging this situation which is not in the rules "easy?" What was your point?

2 hours ago, arnoldrew said:

I don't understand. Isn't any arbitrary decision one might make when judging this situation which is not in the rules "easy?" What was your point?

My point was this seems like the obvious answer, flowing from both a "simulationist" view and the fact that, rules wise, the position of non-leader models in a melee is not very important.

Of course, I also thought allowing the Sabine/Bossk melee in the Invader league final was the obviously correct choice, though it seemed to break a few hearts.