How, exactly, does this card resolve its ability? If I choose two opponents, are their strengths added together? Do we each bid only once?

I don't want to play this wrong, so please help me out! Thanks!

If a player has multiple characters dueling on the same side, they add all the relevant skills from their characters into one number, bid ONCE, and add their bid to their total. So if you duel two enemy characters, they will add their skill together along with 1-5 from the honor bid for their total.

Right on, thank you very much.

How does Hitomi's ability affect Proving Grounds?
If the Hitomi losses the duel to 2 characters who's owner has Proving Grounds - does it trigger Proving Grounds once or twice?

6 hours ago, CollectorOfDreams said:

How does Hitomi's ability affect Proving Grounds?
If the Hitomi losses the duel to 2 characters who's owner has Proving Grounds - does it trigger Proving Grounds once or twice?

With the wording on proving grounds, it does look like you can use it to react on both, since both characters won a duel. I am not sure how often this will come up, though, since it would be a bad play to use her duel where it is not mostly assured to win against an opponent who has proving grounds up

8 hours ago, Chupacabra52 said:

With the wording on proving grounds, it does look like you can use it to react on both, since both characters won a duel. I am not sure how often this will come up, though, since it would be a bad play to use her duel where it is not mostly assured to win against an opponent who has proving grounds up

I feel like there’s a rule saying you can only use a cards ability once per window. So when the duel resolves you could use it for one character winning but not again for the other. I’m not certain on that though.

I have confirmation from Tyler that you can use the two activations of a single Proving Ground if Hitomi loses her duel against two opponents.

It's been a low priority to get this ruling up (here and 5RDB) because I figured it would be a rare occurrence.

11 hours ago, JolOfNar said:

I feel like there’s a rule saying you can only use a cards ability once per window. So when the duel resolves you could use it for one character winning but not again for the other. I’m not certain on that though.

There is a rule that you can use a reaction or interrupt only once per trigger (whether they share a window or not). Since the trigger for Proving Ground is " After a character you control wins a duel ", each character that wins a duel provides a separate trigger (unlike a trigger of "After you win a duel", which could only create a single trigger per duel).