Question from a newbie.

On the Wildfire Plot card :

When Revealed: Each player chooses up to 3 characters he or she controls. Kill each character not chosen (cannot be saved).

And on duplicate card from Reference Guid :

Interrupt : When the overlapping unique card would leave play, discard this duplicate to save that card. (cannot be canceled.)

How the "cannot be saved" effect interract with "cannot be canceled" effect ?

Or more simply, can duplicate save a character from Wildfire plot ?

No, and the way to understand this is to look up the exact definition of "Save" in the RRG:

Save

When a card is saved from an effect that attempts to

remove that card from play, the card remains in play as

the effect resolves and is not considered to have been

killed, discarded, or otherwise removed from play by

the effect.

So the Kill effect has to be applied, then the Save basically overrides the result of the kill effect. Some saves can be canceled, like Bodyguard and Risen from the Sea, so let's look at how that would happen. The Kill effect would come in, be it claim, Put to the Sword, what-have-you. Then you would use the Save ability (emphasis mine):

Initiating Abilities

When a player wishes to marshal or play a card, or

initiate a triggered ability , that player first declares

his or her intent (and shows the card to be used, if

necessary). The following steps are then observed,

in order:

1. Check play restrictions: can the card be marshaled

or played, or the ability initiated, at this time?

2. Determine the cost (or costs, if multiple costs

are required) to marshal/play the card or initiate

the ability. If it is established that the cost (taking

modifiers into account) can be paid, proceed with

the remaining steps of this sequence.

3. Apply any modifiers to the cost(s).

4. Pay the cost(s).

5. Choose target(s), if applicable.

6. The card is marshaled/played, or the effects of the

ability attempt to initiate. An interrupt ability that

cancels this initiation may be used at this time.

7. The effects of the ability (if not canceled in

step 6) complete their initiation, and resolve.

So, if a Cancel to a Save is possible, it would Interrupt the sequence at step 6. However, because Wildfire Assault says "Cannot be Saved," it scotches all attempts because it halts any such considerations at step 1, as it's a Play Restriction.

TL;DR: it doesn't help that saves can't be canceled if you can't even try and save the character in the first place.

I've wrongly considered the "cannot be saved" like a canceling of the saving ability, not a preventing effect. Thanks a lot.

Page 19 of the rules reference states "if an aspect of an ability that removes a card from play is followed by the text 'cannot be saved', players cannot attempt to save that card."