So if i want to issue a challenge to my opponents chaos lord with my wight king, i have to be Base to base touching with the chaos lord? or just in combat with his unit?
Challenges are a bit tricky. Even after playing for many years I still find myself looking up the rules mid-game.
1. Your character/champion issues a challenge, but not to a specific enemy character/champion, just in general.
2. Your opponent can choose to accept or decline. If he/she would like to accpet, then he/she must choose a character/champion model that is in base-to-base contact with the enemy (not the model that issued the challenge per se, just the enemy in general).
3. If your opponent accepts, then he/she moves the accepting model into base contact with the model that issued the challenge.
4. If your opponent declines, then he/she chooses one of his/her character/champion models and moves it to the back rank of the unit. If a back rank does not exist, then the challenge cannot be declined.
In terms of Warriors of Chaos, their character models are forced to always issue and accept challenges. I believe they may even be able to accept challenges without being in base-to-base with the enemy, but I'm not 100% on this.
I don't believe your 4th bullet is correct.
If your opponent declines a challenge, YOU get to pick which character or champion (of the characters and champions that could have accepted the challenge) gets moved out base to base contact.
Also, there is no mention of "ranks" in the description for refusing a challenge. There simply has to be a rank and file model somewhere in the unit that is not in base to base contact with any enemy models. This is most commonly seen when a character on a monster is in combat with a wide unit in a single rank (5x1 cav for example, one model will not be in base to base contact).
If the person challenged refuses, the challenger chooses the character that is retired. Other than that everything else is right.
challenge, as there are no rear ranks for him to be moved to?
(the challenger hunts him down like the cowardly dog he is!).
You don't even need to be in combat with his unit. I've had a game where 5 units were all involved in a single combat. Anyone involved in the combat (touching an enemy base) can issue/accept the challenge. The units do not need to be touching.
On WoC: All chaos MODELS capable of issuing challenges must do so in WoC, as per the wording of the rule, not just characters. So although they won't get an Eye of the Gods roll for killing Char's and Large Targets without a Warshrine, Unit Champions also have to issue challenges (although only characters are inclined to accept, so if your opponent rushes in and challenges first you can decline provided you have only a champion in the unit, therefore he is moved so he cannot fight and thus won't issue a challenge. It's kinda ambiguous in the wording, but there is no FAQ or Errata for this wording so RAW must be applied, and all Chaos MODELS must do so... Sad life for WoC players, one major drawback of unit champions for them.
And another point on the rules for challenges: As far as I know, only one challenge per combat per turn is allowed from what I've been told a few times (although I've not bothered to look it up yet so it might be wrong).
WoC Models that have the rule yes, champions only get the rule if there is a Warshrine present.
And yes only 1 challenge may happen in that combat at a time, but once that challenge is over with then another challenge can be issued the next round.
Kalandros: I recall arguing contrary to that point in many heated debates. Under the Eye of the Gods army-wide special rule, all models that can issue challenges must issue challenges, the Eye of the Gods individual special rule gives a roll on the chart in the event of killing the enemy. It was decidedly remiss of GW not todistinguish between these. The counter-argument revolved around there being no distinction between an army-wide special rule and an individual special rule, and that in effect there was no such thing as an army-wide special rule.
"It's kinda ambiguous in the wording, but there is no FAQ or Errata for this wording..."
...is not correct, it's HERE and the very first question clears the situation up neatly.
Well atleast I was correct in saying what I said. Perhaps I forgot it was FAQ'd and took the rules for granted, or thought I knew this from somewhere else.
Very rarely however; WoC characters must accept challenges, but their unit champions can refuse them if there are no characters present.