The actor explained that he shares many of the same insecurities possessed by Thorin, who undervalues his own ability to lead the dwarf army in taking back Lonely Mountain.
"There is always building within him this paranoia that he's not a good enough leader, and that weighs him down," Armitage told Flicks and Bits. "I have experienced that same feeling as an actor in this role."
He went on to say: "I was aware of taking on the responsibility of that character, so there was something I could latch onto there, as one of the people who loved The Hobbit book and had envisioned that character.
"It took me a while to be convinced that I could do it, it wasn't until I saw some sketches, this one particular pencil sketch… there was something about this character's eyes and the way that his hands are crossed, I thought, 'I think I can do this, I can pull this off'."
[Andy Serkis, Peter Jackson, Martin Freeman, Richard Armitage and Elijah Wood]
The Hobbit: An Unexpected Journey director Peter Jackson recently downplayed the likelihood of Oscar nominations for the cast.
"The acting awards seem to elude us, at least for these types of films. I don't know why," Jackson commented last week.
Jackson's film is released on December 13 in the UK, and December 14 in the US.
Watch a trailer for The Hobbit: An Unexpected Journey below:
Photo Gallery: 'The Hobbit: An Unexpected Journey'