Interpenetration and Recoils with Double elements

That is a good point Haardrada.

In HoTT 2.1, page 16 section two (Interpenetration) says:-
“When an element’s outcome move is insufficient to clear the base
 of an element it is passing through, under or over, it is placed in the
 first large enough unoccupied space beyond.
 When an element’s tactical move is insufficient to clear the base of
 an element it is passing through, under or over, it cannot pass.”

So troops making a voluntary Tactical Move only have their speed to clear the base.
Troops making an involuntary Combat Outcome Move are placed behind the base
(which may mean they exceed their normal recoil distance).

My little group applies the same logic to DBA 3.0...with the extra page 9 provision that:-
“If making a tactical move or fleeing, a mounted element can pass through friendly Psiloi,
 or Psiloi pass through any friends, but in both cases only if there is sufficient clear space
 beyond (see figure 6b) and enough move to occupy it, and either:-
     (a) it starts partly directly in front and ends the move lined-up behind,
          (even if it started unaligned or facing a different direction – see figure 6a)
     (b) or starts lined-up behind and ends lined-up in front.
          (Troops leaving a TZ or fleeing must move in a straight line, so can’t deviate to line-up?)”

Involuntary Recoiling in DBA 3.0 also has other limitations, as noted in Interpenetration on page 9.
Oh, and in DBA 3.0 you can only recoil through one friendly element:-
"...to a clear space immediately behind the first element met (see figure 19d)..."
making recoiling through a column impossible.

We play as above that you Recoil to clear the other element.

A total fix would also allow a Foot Element to Recoil either its base depth or 1/2BW (to make consistent with Mounted and all cleaner Recoils).

TomT

I was waiting to see if anyone else would answer your queries Chris...
...but since they haven’t, I’ll have a go.
Here is what the rules say about your first question.

Recoil distances on page 12 (see also figure 19a).
“A recoiling foot element always moves its own base depth (or ½ BW if this is less than its base depth).
 A recoiling mounted element can choose either to move 1 BW or to move its own base depth if this is less than 1 BW.”

And Interpenetration on page 9 says:-
“If making a tactical move or fleeing, a mounted element can pass through friendly Psiloi,
 or Psiloi pass through any friends, but in both cases only if there is sufficient clear space
 beyond (see figure 6b) and enough move to occupy it, and either:-
 (a) it starts partly directly in front (even if unaligned or facing a different direction – see figure 6a)
      and ends the move lined-up behind,
 (b) or starts lined-up behind and ends lined-up in front.”

“Recoilers can pass through friends facing in exactly the same direction (see figure 6b)
 to a clear space immediately (lined-up) behind the first element met (see figure 19d),
 but only if they are of the right type (a, b, c and d).”

From the above we see that recoiling elements MUST move their full recoil distance, if they can.
If they meet friends they can pass through them (if allowed or if they wish), which means they
will exceed their normal recoil distance, OR, they may push them back (again, if allowed).
If they cannot pass through or push back, then they have met an obstacle, and will halt.
If already in contact with an obstacle, so they cannot move at all, they will be destroyed.

Your second question is a bit more tricky, as it exposes a contradiction in the rules.
Page 12 says “Recoiling or pushed back elements move straight back without turning”,
and “(A fleeing element) turns 180° then moves straight forward without turning”.
However, Interpenetration on page 9 says “they must end up lined-up in front or behind”.
So which is it?
How can those fleeing and those leaving a TZ line-up if they must move in a straight line?

There are two possibilities:-
1) Troops leaving a TZ and those fleeing must move in a straight line, so they cannot interpenetrate if
    facing in a different direction, because they cannot deviate from this straight line in order to line-up?
                                                                   ---OR---
2) Those fleeing can still pass through and line-up, as lining-up is an involuntary outcome of interpenetration?

(Personally, I’d go with option 2, as those fleeing are more concerned with staying alive rather than
following the calm disciplined niceties of who is facing in exactly the same direction.
Anyway, if fleeing troops cannot deviate to line-up, then some players (like me) could exploit this
by having friends facing ever so slightly in a different direction behind the fleeing troops to prevent
them from fleeing too far...such as fleeing right off a table base-edge and being lost)