At first Gwaine appeared to be a funny and carefree man who thought about little more than ale and women. However Arthur, Merlin and Gwen soon learned that he respected honor and loyalty above all else. Gwaine at first appeared to be a simple but noble peasant who came to Merlin and Arthur's aid in a tavern brawl that they were heavily outnumbered in. He ignored Arthur's warning not to step into the fight and proceeded to fight against the pair's enemies displaying impressive combat prowess. He was injured protecting Arthur, showing he was also very selfless.
When Merlin asked why he does not reveal his noble past Gwaine revealed his humble nature by telling Merlin his lifestyle has taught him that titles are not important. He wants to be treated by his character and skills and not by his family name. Also he preferred the freedom of the vagabond lifestyle.
Gwaine generally disliked people of royal blood seeing them as corrupt and power-hungry. However he soon grew to respect Arthur, even referring to him as a friend at one point. He was also unafraid of criticizing Uther Pendragon in front of Arthur saying that he may one day be able to return to Camelot when it was ruled by a "half decent king".
Gwaine appears to have a very trusting nature, revealing the truth about his father to Merlin and empathising with Merlin when he told him about his own father, Balinor. Gwaine stated that Merlin and Arthur were the only friends he had. He also had a good sense of humour and was cheerful and optimistic even while he was a prisoner of Jarl.