Sturlaug joined Thor's Bilskirnir Warriors as many other young norsemen in tribute to the mighty thundergod Thor!
When there were no raids being prepared in the homeland, the only way to prove that you were a man, was on the field.
And it was on this field Sutlaug got his first kill, and in his very first game. He faced a fierce warrior woman, she was worthy to be a shieldmaiden and thus it was not a shameful act to send her to Asgard.
And in this battle he learned some dirty tricks indeed, and he was sure he would be able to use these tricks many times on the playing field in the future.