Does the supporter get to declare defenders before or after the Lord Commander has the opportunity to take on the challenge (assuming a MIL challenge and no defenders declared)?

Support

In addition, when a player you support is attacked by another player, if the defending player declares no defenders, you may declare any number of your own eligible characters as defenders to that challenge.

Lord Commander of the Kingsguard

When an opponent is attacked by another opponent in a MIL challenge and decides not to declare any defenders, you can use this title to change the target of the attack.

Bonus question: since both of these effects refer to not declaring defenders, are they usable if some character becomes a defender through a card effect (Horseback Archers, Catelyn Stark LoW)?

If you look in the FAQ, you'll see that the Lord Commander works as a cancel, jumping the challenge backwards and allowing the attacker to reassign stealth against the Lord Commander's characters, Supporting does not allow this. So, since Lord Commander is a cancel effect, it comes before the non-cancel of supporting. That means the Lord Commander always has the first choice to take the unopposed military challenge.

And yes, because they are both worded in terms of declaring defenders, it doesn't matter if there are defending characters in the challenge through other means when the redirect happens.

You have proposed a different answer in this thread :

http://www.fantasyflightgames.com/edge_foros_discusion.asp?efid=18&efcid=4&efidt=189449&efpag=0#192021

I'm not sure if the Title errata came in between.

However, I would say the support comes first. The timing being as follows for the "declaring defenders" framework event :

1. Initiation - defending player choose (or do not choose) defenders - that's when Support can be declared

2. Save / Cancel - that's when the Lord Commander can redirect the challenge (if no defenders have been declared in Step 1.)

3. Resolution - characters choosen in Step.1 are declared defenders and knelt successfully

One may point that defenders are only choosen and declared in Step 3, thus the Support would come only in Step3., after the Lord Commander. However, if defenders were declared at Step 3., it would lead to this : the Lord Commander can always redirect any challenge, since defenders would never have been chosen at Step 2. This being not possible, the only possibility is that a player choose if he is going to defend or not in Step 1 - and choose the characters. So the Support can only happen during that step, before the Lord Commander.

Bolzano said:

Bolzano said:

That was how I was interpreting it before in the other thread, too, but with Lord Commander having effectively the same timing (since it has pretty much the same play restriction of not declaring defenders). So the full resolution of "declare defenders" included the support opportunity, which Lord Commander had to wait for. Now, since Lord Commander is a cancel and we know that no cancels can come after Step 3's successful/unsuccessful determination, no matter how nebulous the wording of the effects, it had to be moved to Step 2, putting it before the "supports" mechanic.

Bolzano said:

However, with all of the new rulings for "then" and for "support" confusing the timing, it's probably simpler to say that the since the conditions for when you can use them (Lord Commander or Supports) is the same, the First Player gets to decide who gets first crack at it.

I think you misunderstood my point on declaring defenders on Step 1.

They way I see it, they do not kneel during Step 1, as you also say - but the player just choose some characters that he wish to be declared as defenders.

Only if they are declared successfully, will they be knelt and enter the challenge in Step 3). Otherwise, if any cancel occurs, they will be declared/knelt unsuccessfully.

Look at it with this example from FAQ :

"A) The first challenge resolution framework
event is initiated (step 1), determine winner
of challenge. The strength of the two
opposing sides are totaled and compared (with
Baratheon having the most STR)."

We can see here that something may happen in the initiation phase of a framework event - be it counting STR, choosing legal targets, or choosing which defenders will be declared (and not declaring them successfully).

However, I also first thought that the First Player should decide - but Titles are not passive effects so I don't think the rules really allow the first player do choose it (it may be a good interpretation, though).

Might be worth to get a clarification on this

Here is the clarification:

Question to Nate French :

"2/ In a meelee game, when no defenders are declared in a challenge, who gets the first opportunity to defend/redirect between the Lord Commander of Kingsguard Title and the player supporting the defender?
According to the FAQ, the military Title is used as a cancel to the framework event of declaring defenders. So initiation step 1) of declaring defenders has happened, but not Step 3) ( = no defenders have been declared).
However, the definition of supporting player is not a cancel in the FAQ. So who gets the opportunity first: First player, Support or Commander of Kingsguard?

You previously answered me the following which I didn't really understand so I have explained the problem more clearly:

"This title can only be used if defenders are not declared. The opportunity to declare defenders occurs, and if none are declared, the opportunity to use the title arises.""

And his answer :

Martell is happy and Stark is screwed