You've all heard the phrase "Three steps forward, two steps back."

I am trying to figure out the probability of returning to my starting point if the number of steps forward is determined by rolling one six-sided die and the number of steps backward is determined by rolling another six-sided die.

Let's call rolling both dice a "trip." So if I roll a 3 on die #1, I go forward 3 steps, and then I roll a 2 on die #2, I go backward 2 steps. My total distance covered in the 'trip' is 1 step.

What is the probability that I return to the origin after 1 trip? What is the probability after 2 trips? What is the probability after n trips?