Getting back into this.

1) If a character's die is in my dice pool and that character is defeated, does the die get discarded? The rules seem to indicate they do, just checking.

"When a character has damage on it equal to its health, it is immediately defeated. Set aside its character card and all of its dice (both its character and upgrade dice), and discard all upgrades on it. (While set aside, the character and its dice are no longer in play and cannot be used.)"

2) If I play Abandon All Hope on my opponent who does not have any resources, could they choose to 'discard all of their resources' or do they have to discard their hand?

"ABANDON ALL HOPE (79) • Either option can be chosen, no matter how many resources or cards in hand a player has."

3) Playing a lot of L5R lately where the game state must change. L5R is clearly not Destiny and I'm thinking you can do things in destiny that don't change the game state. Is this a correct assessment?

"Can I exhaust or play a card that has an action that I cannot fully resolve in order to stall the round? Like a Backup Muscle (r99) with no damage on it or playing Noble Sacrifice (r118) when I have no Blue characters. • Yes. Playing a card from your hand, even if it has no effect, removes a card from your hand and does not count as doing nothing. The same applies to exhausting a card or rerolling a die to its same side."

Thanks in advance!

1) You are correct, all dice and upgrades attached to a character, even if they are still in your pool, are removed. Upgrades (excluding redeploy upgrades) go in your discard pile. All of the dice go into your set aside zone. The exception to this are the Death Trooper dice rolled in by Krennic and the ID-9 Seeker Droid rolled in by Seventh Sister. That is because those dice aren’t attached to the character, they are just in your pool as a result of your character’s ability.

2) Yes, when a card offers your opponent a choice, they can choose the option that does nothing to them. So with Abandon All Hope, if they have no resources they can still choose to discard no resources. If they have no cards they can choose to discard no cards. And this goes for anything that offers your opponent a choice.

For 3) No. You do have to change the game state with whatever action you take, but you do have the option of Passing which is not taking an action. The quoted example you provided is indeed changing the game state because the player that played a card they couldn't fully resolve ends that action with one less card in their hand. The sort of things you can't do is like choosing to Resolve Dice of a symbol that you don't have in your pool, no game components move or change states so that action would be invalid.

3: If you take an action that literally does not change the game state, you are considered to have passed instead. This is relevant because it gives your opponent a chance to pass themselves, thus ending the round.

But there are several things you can do that have no other effect on the game state outside of the act itself. Added in RRG 1.6 is that you can discard a card from your hand to reroll 0 dice. The game state has still changed: You have 1 less card. So that's not a pass, and legal.

When it comes to playing cards that have no effect, again, the game state has at least changed in that you have 1 less card in your hand. Note that you still need to meet the play restrictions (play only), and pay the card cost. Note note: Spot X is not a play restriction. If you attempt to play a card and can't meet the Spot X requirement, the card does nothing more, although you do still pay the cost.

Have they ruled if exhausting a card is changing the game state, even if it does nothing? I was under the assumption that exhausting Backup Muscle, but moving zero damage still changed the game state because a card that wasn’t exhausted now is. Haven’t seen a ruling specifically on that yet. Anyone know?

9 minutes ago, gokubb said:

Have they ruled if exhausting a card is changing the game state, even if it does nothing? I was under the assumption that exhausting Backup Muscle, but moving zero damage still changed the game state because a card that wasn’t exhausted now is. Haven’t seen a ruling specifically on that yet. Anyone know?

From the OP, which is quoted from the RRG FAQ:

23 hours ago, The Laughing Monk said:

"Can I exhaust or play a card that has an action that I cannot fully resolve in order to stall the round? Like a Backup Muscle (r99) with no damage on it or playing Noble Sacrifice (r118) when I have no Blue characters. • Yes. Playing a card from your hand, even if it has no effect, removes a card from your hand and does not count as doing nothing. The same applies to exhausting a card or rerolling a die to its same side."

So yes, exhausting Backup Muscle when it has no damage is still changing the game state and is a valid action

16 hours ago, SwagonBallZ said:

From the OP, which is quoted from the RRG FAQ:

So yes, exhausting Backup Muscle when it has no damage is still changing the game state and is a valid action

The reason behind this is that other game effects can be triggered by these acts. So while the game state after the action may look the same (as in the case of re-rolling a die and having it come up with the same symbol), the state has actually changed because there was a trigger opportunity, regardless of whether anything was actually triggered.