So this came up today in a casual game. Can I use overconfidence if there's only one die in the pool?

This is a slippery B.S. ruling that stems back to Let the Wookie win. You can pick something that does not exist as an option. So with that messed up thinking! A blank or special counts as zero and therefore in the case of a tie you would get to choose (wording on the card). Otherwise the dice that doesn't exist is still a zero choice, IE non effect choice. So yes you can but if they do not role a blank or special it has no effect because they (or card effect) get to choose the dice that isn't there. I know it's screwed up.

I had a good track record on rules interpretations in Awakenings. I also felt comfortable with my understanding of the rules as of the first set. However, I'm not as confident going into SoR. Nonetheless here is what I think.

OVERCONFIDENCE

Spot a Blue character to reroll 2 dice. Then remove one of those dice with the lowest value (you choose in the case of a tie).

If there is only one die to reroll you may pay 1 resource and reroll it. You just followed as much of the text as you could. Since you didn't do everything you were supposed to (roll 2 dice) you may not complete any of the text after "then".

I am not really sure this is correct, but it is how we've been playing it and will continue to play it until we see an official ruling.

1 hour ago, ozmodon said:

This is a slippery B.S. ruling that stems back to Let the Wookie win. You can pick something that does not exist as an option. So with that messed up thinking! A blank or special counts as zero and therefore in the case of a tie you would get to choose (wording on the card). Otherwise the dice that doesn't exist is still a zero choice, IE non effect choice. So yes you can but if they do not role a blank or special it has no effect because they (or card effect) get to choose the dice that isn't there. I know it's screwed up.

Well, something here is certainly screwed up...

1 hour ago, Starbane said:

I had a good track record on rules interpretations in Awakenings. I also felt comfortable with my understanding of the rules as of the first set. However, I'm not as confident going into SoR. Nonetheless here is what I think.

OVERCONFIDENCE

Spot a Blue character to reroll 2 dice. Then remove one of those dice with the lowest value (you choose in the case of a tie).

If there is only one die to reroll you may pay 1 resource and reroll it. You just followed as much of the text as you could. Since you didn't do everything you were supposed to (roll 2 dice) you may not complete any of the text after "then".

I am not really sure this is correct, but it is how we've been playing it and will continue to play it until we see an official ruling.

It looks correct to me.

“THEN” EFFECTS
In order to resolve an effect that is preceded by the word
“then,” the previous effects on the card must have fully
resolve.

I thought about the "Then" part so I looked it up. You got it right.

9 hours ago, Starbane said:

OVERCONFIDENCE
Spot a Blue character to reroll 2 dice. Then remove one of those dice with the lowest value (you choose in the case of a tie).

If there is only one die to reroll you may pay 1 resource and reroll it. You just followed as much of the text as you could. Since you didn't do everything you were supposed to (roll 2 dice) you may not complete any of the text after "then".

I am not really sure this is correct, but it is how we've been playing it and will continue to play it until we see an official ruling.

That makes sense! I just couldn't "see" the key word to follow, in this case it's "then".