Merrill/Approval

Friendship
Merrill's friendship can be gained by:
 * Siding with the mages or the elves in quests.
 * Choosing options that favor blood magic or demons.
 * By being agreeable to her in conversation.

Act 1
 * Act of Mercy Tell Grace that you will distract the Templar (Thrask). Choose the agreeable options and then "Murder is too far." This will earn you (Confirmed).
 * An Errant Letter Keeping Thrask's secret: (Confirmed)
 * Enemies Among Us The final conversation with Cullen in the Gallows Courtyard can earn up to friendship points. In the beginning of the conversation, respond "Not all mages are like that" and you will receive . Later in the conversation, choose the response "You're wrong" and you will receive.
 * Finders Keepers Attempt to trick the guards at Woodrow's Warehouse:
 * Magistrate's Orders Choosing to kill Keldar:
 * Shepherding Wolves Accept the quest from Sister Petrice: ; Refuse to hand Ketojan over:
 * Tranquility Promise not to harm Anders:.
 * Wayward Son Telling Vincento to make it up to his son: Choosing to let Feynriel go free:
 * Visiting the Gallows with Fenris in the party will initiate a dialogue amongst your party members. If Merrill is present, choose the "It is wrong to oppress Mages" option:
 * Bait and Switch Let Merrill defend herself at the end:

Act 2
 * Forbidden Knowledge: Choose to use or take each evil tome in the sidequest: for each tome not destroyed while Merrill is in the party
 * Night Terrors Tell Marethari that you will not kill Feynriel:
 * Wooden Halla If you are already on the path of friendship with Merrill, then any response will earn you a

Act 3 }}
 * A New Path: When talking to Merrill to initiate the quest, agree without suggesting she talk to the keeper first:
 * A New Path: Ask Marethari how to fix the eluvian:
 * A New Path: After the battle with the demon tell Merrill that Marethari was stupid:

Rivalry
Rivalry with Merrill can generally be earned by contradicting the "hows" of developing a friendship with her, as mentioned above.

Act 1
 * Act of Mercy Telling Grace to go back to the circle:
 * Wayward Son Convince Feynriel to go the Circle:
 * Welcome Home "Don't Thank Me":
 * Magistrate's Orders Choosing to help Keldar:

Act 2
 * Forbidden Knowledge Destroy each evil tome in the sidequest: for each tome destroyed while Merrill is in the party
 * Mirror Image Refuse to do the quest. The quest will still be available, though.
 * Mirror Image: Tell Merrill that Pol ran away from her because he is a coward (aggressive option), after defeating the Varterral:
 * Wooden Halla If you are already on the path of Rivalry with Merrill, then any response will earn you a
 * Back from Sundermount: After NOT giving the Arulin'Holm to Merrill (as the Keeper requests), tell Merrill that you are trying to help her (agreeable tactful option), or that she can't complete the mirror (wry, humourous or witty option): You get for either of these. Telling Merrill you don't trust her with the tool (aggressive option) instead, only nets you.

Act 3
 * A New Path: When talking to Merrill to initiate the quest, suggest she talk to the keeper first:
 * A New Path: Telling the rest of her clan that you will take responsibility for Merrill's actions:
 * A New Path: After the battle with the demon, tell Merrill that she should have listened: