Flies and Spiders wrote:Playable on a character facing a Spider attack. If the strike is successful, target character is not harmed and is taken prisoner at a Ruins & Lairs []. During his untap phase, make a body check for that character modified by +1. If not eliminated, his player then makes a roll adding his body. If the result is greater than 15, the character is automatically rescued into his own company located at the rescue site.
Rescue-attack: Spiders — 3 strikes with 9 prowess.
For comparison:The Ring Will Have But One Master wrote:Playable on the bearer of The One Ring. During each of his organization phases, one character (other than the bearer) in bearer’s company is discarded (of bearer’s player’s choice) along with all non-follower cards played with him. During his organization phase, the target character may tap to attempt to remove this card. Make a roll—if the result is greater than 8, discard this card. Cannot be duplicated on a given character.
Flies and Spiders AND The Ring Will Have But One Master do not specify an exact moment of triggering of actions they create.Spells of the Barrow-Wights wrote:Playable on a character facing an Undead strike. If the strike is successful, target character is not harmed and is taken prisoner at a Ruins & Lairs []. Character must discard any rings along with his other items. At the start of each of his untap phases, make a body check for that character.
Rescue-attack: Undead — 3 strikes with 8 prowess.
Die roll actions may be targeted by other actions declared in response in the same chain of effects. But it is unclear (for me) whether the actions created by the two cards are declared at all.
Maybe the two cards are candidates for errata.