Anytime you roll the dice you need to roll under one of your 4 stats. Here's an example.
You want to attack a monster with your sword. Start with your weapon skill of 25. Lets add some bonuses:
+10 for having a sword
+10 for knowing about dueling from your career
+10 for the point of Advantage you get for charging into combat
You need to roll under 55. You get a 36, success! You do 3 points of damage.
I hope that clears things up! Thanks for the question.