Found this thread over a the geek. Thought some people here might have the same timing question.

[q=quinnox]Its one of the rulings that we don't use. We don't think it makes sense, so we play it does not get the bonus.

The game has had some loopy rulings to be honest. We also don't play the corruption ruling according to the official rules, it makes Chaos faction and the tactic seduced by darkness way too weak.
We play that you can corrupt attackers and defenders when they are announced with seduced by darkness. It seems much more natural.[/q]
I think you are misunderstanding the timing and action windows in the Battlefield phase. There is an action window between "Declare Zone to be Attacked" and "Declare Attackers".

See page 10, phase 4 of the official FAQ:
http://www.fantasyflightgames.com/ffg_content/warhammer_lcg/support/wh-faq-v1.pdf

Phase 4. Battlefield Phase
(Numbering added for clarity)
1) Active player decides (declares) which of his opponent’s zones he is attacking.
2) Actions may be taken by either player. (This is the point where Seduced By Darkness should be played in order to prevent a unit from assigning as an attacker due to corruption)
3) Active player declares attackers. (note: player is not required to assign any attackers)
4) Actions may be taken by either player. (Playing Seduced by Darkness at this step or any subsequent step does not prevent the target creature from participating in the battle. Although it is corrupt, it has already been assigned)
5) Defending player declares
defenders.
6) Actions may be taken by either player.
7) Damage is counted then assigned, without yet being applied.

Of course you're free to play this game however you wish, but corruption means you can't declare a unit an attacker or defender.

This is clearly described on pg 17 of the original rulebook. My advice is to play the rules as stated. I think it helps the integrity of the game to have one set of rules. There may still be some gray areas in this game and how to play some cards, but corrupting a unit after it is declared doesn't stop that unit from participating in battle if you choose to play it correctly. There is no grey area on this subject.

Yeah, the rules are pretty clear on this one. I don't see why they need to be amended...It certainly does not make Chaos weak...sheesh.

It would have if the window for playing actions was removed, (as the faq originally was suggesting), between declaring the zone to be attacked and declaration of attackers.

You can stop a unit from attacking right before attackers are declared. So a zone is picked, then actions are taken before the attackers are declared. Corrupting a unit at this time would stop a unit from being declared. Once declared, they can still be corrupted, but it won't stop them from attacking on that turn.

There was a mistake in the FAQ that followed the mistake in the rulebook in the timing chart. It has been rectified.

Though, even if it had been Chaos could have corrupted the units before the end of the Capital Phase (when your opponent plays his last unit, corrupt one, then ask if he has any responses or actions, then corrupt another, so on and so forth).

I also don't see the timing issue. Corrupt the units before the capital phase. Then deal heck-a-damage your next turn.

Stop using logic.

dormouse said:

There is a huge diffrence between using seduced by darkness at the end of the capital phase and between declare the zone to attack and introduce the attackers.

When the active player is alerted that he can no longer use the most important unit to attack (f.e. he counted the damage he can assign to reach his goal) he will just end his turn without the attack.

Now, when he has already declared that he wants to attack a zone, he has to, even if that ruins his plans. Assume that he calculated he will do 4dmg with 2 spider riders to Chaos knights if they are declared as defenders. Killing this unit satisfies him. He declares a zone to attack. The chaos player plays corruption, so the orc player can no longer do 4dmg. just 2 instead. That ruins his plans as he not only won't kill chaos knights but surely he will loose one reamaining attacking unit. Clear? I assume that when an attack on a zone is declared u can't pull back.

I believe you may be wrong, if you declare an attack on a zone and someone you were planning on attacking with is no longer available to you then I see no reason why you would have to carry through with the attack. Also sending in one Spider Rider twice to attack and do 2 points of damage and potentially lose it is not really substantially different (in isolation) from sending two Spider Riders and and doing 4 and losing one. For every negative reason that comes from this including your opponents actions there are things that could make this more beneficial, including your own actions.

None of this matters though because as it has been pointed out, there is still an action window between declare zone and units.

dormouse said:

One point I see is that if you Declare Zone, then in the Action Window, you take the first Action to lay some groundwork against defenders and then your best Unit is corrupted, your groundwork won't pay off and you used by a card and resources that would've helped you do more damage if that had been combined with an attack by all your Units.

dormouse said:

Even if there is one more unit that can attack? So you can declare a zone to attack and then wdeclare 0 units? If yes then my doubts are groundless.

dormouse said:

There are plenty reasons why killing Chaos Knights might be more beneficial, f.e. If it took place in kingdom, chaos player will gather 3 resources less next turn which might be crucial.

I'm sure you know how even 1 resource less changes our decisions on the next move.

We are talking about corrupting units before they attack, killing off an attacker is not going to change your resource pull in and of itself. I'm not sure where you were going with your second statement.

I'm a bit confused about this thread. As I understand the original post it is accurate and not requiring of any special rules changes. Did the latest FAQ change it to make the post accurate or am I understanding the post wrong?

There was a mistake in the original FAQ that propagated a mistake in the timing chart in the Rulebook, that show the declare zone and declare attacker as part of the smae step with no action window in between. It was immediately corrected. That is what prompted this thread.

dormouse said:

Defender. Killing a defender, not an attacker. In my example Attackers are 2 squads of Spider riders in the battlefield and the defender is a squad of chaos knights in the kingdom zone. Surviving chaos knights DO change everything as the player controlling chaos knights will gather 3 gold more his turn.

The point is whether or not is it possible to corrupt units during the battlefield phase in an action window between declare the zone and declare attackers as things are.

If I am corrupting potential attackers or defenders before attacking units are declared then that vastly affects who is going to be able to participate. Each corrupted unit removes one which could be killed by the combat. If I am the defender knocking out potential attackers will more likely keep my defenders alive and knocking out potential defenders will likely keep more of my attackers alive as well as allow for more damage to get through to the zone.

Being an attacker down in my battlefield whether it happened at the end of my Kingdom phase or after I have declared a zone is more or less immaterial. Unless we have confirmation that once an attack has been declared that I am forced to see it through even if my planned attackers are no longer able to be declared there is no difference. If I choose to attack anyway, then yes I am more likely to lose an attacker where I may not have before, and yes it gives them an additional turn for drawing resources, pulling gold, or having an increased attack strength... I also have the same chance of drawing (or having had drawn) additional units/supports to supplement my own, or corrupt in return... which was my point, that for each advantage there is a neutralizing advantage available for the other side.

The real difference comes in who has board advantage (who is drawing more cards, pulling more resources, the greater battlefield strength etc.), that is the player who is going to be in a better position to handle corrupting/corrupted forces, regardless of which way the rule had been.