Hi Futuremc002,
Having spoken with Christian he has said that it mostly works as Troika! does so:
Generally speaking anything that's easy or non critical to the game doesn't require a skills check it can just happen.
Anything that needs to be checked requires a player to roll under their skills (2.1.1 p32).
For example a player has a skill of 5 and an advanced skill of 3 in climbing.
They need to roll under or equal to an 8 on 2d6 to succeed the challenge