You cannot include more than 15 neutral cards in your deck.

Action: Kneel your faction card to reduce the cost of the next loyal card you marshal or play this phase by 1.

Magali Villeneuve
Core Set #27.

Link: Decklists


Rules FAQ

Fealty reduces the cost to marshal (e.g. pay gold, during the marshaling phase, to bring characters/attachments/locations into play by the default game rules), and to play (a term reserved for events), but has not impact on effects that "put into play". It will not lower the cost to ambush a card, bring a card out of shadows, or use abilities like Ser Aliser Thorne.