Tuesday, 3 April 2018

ADLG: Evade Moves

I am sure my need to understand evade rules must have something to do with my penchant for Mongol cavalry armies.  They need to do a fair bit of evading to be effective.

In my experience implementing simple tabletop rules to allow troops to retire in the face of an enemy is a real challenge for rules writers.  So much can happen that the rules have to cover lots of eventualities.  Inevitably some outcomes get missed.  Sometimes the complexity defeats the author and the rules end up badly written.

Evade rules are such a perennial problem (for me?) that I've already written posts covering fleeing and evading in DBMM and Field of Glory respectively.  Now it's the turn of Art de la Guerre (ADLG) but before I do I'd like to mention something from an earlier post.

In 2009 John Garvey made the point that, at a conceptual level the [DBMM flee] process is simple:
  1. Start the flee move by turning the fleeing element; usually to point away from the threat.
  2. Check to see if the flee move places the element in further jeopardy; such as reaching impassable terrain. If not then flee.
  3. If there are problems with the original flee move, check if they can be avoided. If so turn the element a second time and then flee.
  4. If the problems can’t be avoided flee in the original direction and face the consequences.
Although written nearly ten years ago, and specifically about DBMM, it's a surprisingly good description of the ADLG evade process: plus ça change, plus c'est la même chose?  As always the real complexity comes from the implementation and the application of various limiting conditions.

If you don't like flow charts look away now.

Evading in ADLG is split in two. The first is simply a check to see if there's anything close by and blocking the path of the evading unit. The second is the evade move proper but it also deals with enemy, obstacles and friends that the evading unit may encounter along the way.

I've not "looped the process" in Part#2 to deal with multiple obstacles.  This would have made the diagram far too intricate and defeat its primary purpose. Just remember no matter how many obstacles you're trying to avoid only one slide is allowed per evade move and multiple wheels are allowed providing they total no more than 90 degrees.

Please note the charts do not include the distances involved.  It is safe to say that any slide, wheel or movement in rough or difficult terrain reduces the distance the evading units puts between itself and the charging unit.

Part #1 is fairly basic.  It treats enemy, friends and terrain differently.  The latter two are grouped as obstacles but only if the friends cannot be interpenetrated. In the text on page 38 it is implied that if you can interpenetrate a friendly unit you should do so: I would have liked this explicitly stated on page 38; it is mentioned but right at the end on page 39.

Part #2 looks a very smooth process and appears well thought out but it's not really.  I am learning that ADLG often contains strict sequences that are crucial and sometimes well hidden if not missing.  This is a good sequence example: avoiding obstacles is done either by sliding or wheeling in that order.  However as written the sequence is missing something. At the end the evade rules on page 39 there is mention that groups "may be compelled" to contract to bypass an obstacle but there's no mention of when this should happen.

After some help from the ADLG forum (see comments for a link) the strict sequence is that a group may contract to evade but only after "attempting" and failing to pass the obstacle by either sliding or, if that fails, by wheeling.  It's worth noting that if a slide doesn't work you can't combine it with a wheel to get past an obstacle: it's one or the other.  However any contraction can be combined with a wheel as normal.

To complicate matters a touch there's no requirement to keep the group together and individual units can take separate paths but you only roll once for the group not for each unit in the group.

Download the flow charts.

What concerns me slightly is that, where allowed, the avoidance mechanisms are different in Parts 1 (slide) & 2 (slide or wheel or contract).  This is another ADLG difference to remember.

I found a second omission.  I don't know if this happened during translation or it stems from the rules. Whilst drawing the above I started to wonder what happened when, after you've started to evade, the evading unit meets something it could not get past?  Multiple readings of the rules and the FAQ left me none the wiser.

The solution, included above, came courtesy of Mick Hood (ADLG supremo in the Northern League) who pointed out that the evade simply stops 1 UD (unit of distance) from the object that can't be bypassed.  Logical, simple, consistent with the rest of the rules and completely absent from the text even by implication.

Having found two omissions in two pages I also found one error and one bit that really puzzled me:
  • In the bottom right hand diagram on page 39 a unit of light horse is shown evading and avoiding enemy troops.  Part of the diagram shows it approaching an enemy unit head on and wheeling 90 degrees to avoid them and moving to its left.  Nothing wrong with that you might think but the rules say you can only wheel within 1 UD (which is the same as base width).  Wheeling at this distance would leave the evading unit with it's side edge in contact with the enemy front edge yet the diagram shows a clear gap.
  • In section 4 on page 39 it says that, if not blocked, an evading unit can wheel to align it's orientation parallel to the direction of the charge at the start of the evade movement.  No problem; although I can think of situations when this would be sub-optimal.  What puzzles me is that it goes on to say that this can't be used to avoid a blocking obstacle.  This is nonsense: if there's a blocking obstacle section 4 doesn't apply!  I can only assume it's been written to close a sneaky loophole someone tried but this restriction would have been better in section 3 not section 4.
That's it for the ADLG evade rules.  A bit tougher than I thought at the outset.  If spot any mistakes or you know of errata or clarifications I've missed please leave a comment and I'll update the post.


  1. Changed section dealing with group contractions. Still not sure this is correct. Seeking confirmation elsewhere and will report back.

  2. Updated diagrams and text to clarify issues around group contractions.


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