Not much is known of Addvar's past, apart from dialogue that includes his mentioning to Sorex Vinius that he is not originally from Skyrim. He is also the only known merchant to sell the woodcutter's axe, which is used to chop firewood.
The Dragonborn may receive a letter from Addvar asking for "assistance" after assaulting Taarie, who owns the Radiant Raiment clothier in Solitude. The Dragonborn may also receive a different letter from Addvar after assaulting Captain Aldis.
Svari: "They can't hurt uncle Roggvir. Tell them he didn't do it."
Addvar: "Svari, you need to go home. Go home and stay there until your mother comes."
Aldis: "Lock the city gate."
Vivienne: "You should tell her that her uncle is scum that betrayed his High King. Best she know now, Addvar."
Addvar: "You're all heart, Vivienne."
Aldis: "Roggvir. You helped Ulfric Stormcloak escape this city after he murdered High King Torygg. By opening that gate for Ulfric you betrayed the people of Solitude."
Sorex: "He doesn't deserve to speak!"
Roggvir: "There was no murder! Ulfric challenged Torygg. He beat the High King in fair combat."
Roggvir: "Such as our way! Such as the ancient custom of Skyrim, and all Nords!"
Vivienne: "Cut 'em down!"
Aldis: "Guard. Prepare the prisoner."
Roggvir: "I don't need your help."
Aldis: "Very well, Roggvir. Bow your head."
Roggvir: "On this day... I go to Sovngarde."
Addvar: "Svari, Jala said you stole an apple from her cart yesterday. Is this true?"
Svari: "Just a little one! I was hungry!"
Greta: "I'll talk with Jala, dear. I'm sure she'll accept a potato as repayment."
Addvar: "I suppose. But Svari, we don't steal. We're better than that. Understand?"
Svari: "Yes, papa."
Greta: "Eat up, Svari."
Svari: "Fish? Again?" or "Potatoes? Again?"
Addvar: "It's all we've got for today. Don't be greedy."
Greta: "Maybe we'll have better luck tomorrow."
Addvar: "We'll make it, Greta. We always have so far..."
- It is possible to receive a letter from Addvar saying, "I know you killed her, don't worry, I'm actually glad she is dead."; this can happen if the Dragonborn kills Jala, in Solitude. After killing her, a journal entry is added saying "Report success to Addvar," which possibly hints at an unfinished or glitched quest.