As an example, when recruiting a leader an action card is chosen that has an immediate ability and it displays two leaders. One of the leaders has been captured, and the other leader is in play (and has neither been captured nor lured to the Dark Side).
The FAQ wrote:
Q: When recruiting leaders, can a player choose an action card if all leaders on that card have been eliminated or captured?Obviously in my example no leader can be recruited. If both leaders had been captured, eliminated, or lured to the Dark Side it is clear that any immediate ability of the card could not be used. However, can the immediate ability of the card be used in my example since one of the leaders has not been captured, eliminated, or lured to the Dark Side?
A: Yes, the player can choose any card they wish. However, the player cannot recruit a leader if all leaders on the card have been captured, eliminated, or lured to the Dark Side. Any “Immediate” abilities on the card have no effect, and the card is discarded.