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.

Can I support with no defenders?

Bear with me on this.

Let's say I'm playing Martell and the table has decided they don't want to attack me with 4 Str in case I start to trigger all my shenanigans. If there's an unopposed challenge that I can jump in the way of, can I declare my support and promptly assign nobody so I can mess with their chi?

Well it is also stated that if you go to support and lose the challenge, the original player is still considered the losing opponent in the challenge. So no, you couldn't.

Staton said:

If your characters defend a challenge in support of another player, you are considered the winner (or loser, depending on the results) of the challenge, but the original target of the challenge is still responsible for any claim that would need to be resolved

Actually according to the rulebook you are considered the winner or loser, but the original target settles claim.

Oh dang, you're right. I was thinking of the fact that they'd have to fulfill claim. Then the answer would still be no. Part of supporting is declaring defenders. So it'd be like trying to initiate a challenge without declaring attackers. If you want to support an uo challenge you need to declare defenders.

Hmmm OOH Cat O The Canals it is then.

Staton said:

But it says "any number" ... is not 0 a number?

CCG logic is never equal to mathematical logic... don't get me started on Anachronism that said 0 was neither odd nor even!

I have to say it once in awhile: Staton is correct here.

You take over defending in the "supports" situation by declaring defenders. Announcing your intention without commiting characters doesn't complete the requirements for the mechanic. If you declare 0 defenders, you really haven't done anything as far as the "declare defenders" framework event is concerned.

ktom said:

I happen to agree, if for no other reason than to not give Martell players free loss triggers with no downside to themselves.

However, I might also suggest that FFG consider rewording the text to "by declaring at least one defender".