Rules FAQ
Abilities on event cards like Saving the Kingdom or Beneath the Petals that work while the event is not in your hand can still be canceled, because triggering those abilities is not considered to be playing the event. (See Playing Events.)
If you put a card directly into play from shadows without paying its shadow cost (for instance, Forest Patrol), you will waste the reduction provided by Conspirator's Blade for the next card.
Rules FAQ
The ability affects all players, including the controller of Dirk.
If an ability discards multiple characters at the same time (for instance, Varys (Core)), the forced reaction triggers for all of them.
Other reactions to a character being discarded or placed in the discard pile can no longer interact with that character after it is placed in the dead pile. This includes cards like Citadel Archivist, Ser Addam Marbrand or Saved by the Watch, among others. On the other hand, reactions to a character entering the dead pile (like Warlock of Qarth or Maester Cressen (WK)) can be triggered after Dirk resolves.
A character that is sacrificed is not discarded from play. Those are two separate effects.
If a character is saved from being discarded, Dirk's reaction does not trigger, nor does it interact with duplicates being discarded in any way.
Rules FAQ
You do not have to state which icon you intend to remove before a cancel can be used.
You can choose an icon the character currently does not have.
Removing an icon while a character is already participating in a challenge does not directly affect that challenge, but it could matter for abilities like The Red Viper (OR) or Sandstone.
Rules FAQ
The post-then part of the ability resolves before any reactions to the character entering play.
If the opponent has no cards in hand to discard, you still draw a card. Similarly, if you cannot draw a card, the opponent must still discard one. Resolve as much of the effect as you can.
Rules FAQ
If you have multiple copies in play, their effects are cumulative, so you can potentially keep up to 3 unspent gold for the following round.
You can choose your own characters with the reaction.