Athletics - Climb

A Climb skill check should only be rolled where there are reasonable chances of falling. Someone climbing up a ladder, even with missing rungs, should not have to roll unless they are threatened or distracted. Even then, if the fall would make them drop so low that there would not be any consequences, beside obvious shame, it is not worth rolling for.
The difficulty for an Athletics - Climb check is relative to a given surface.
EXAMPLE #1 OF A CLIMB CHECK
Declan is attempting to seal a strange artifact from a wealthy estate. Declan successfully snuck through the patrols around the manor and now has to climb the wall to reach the treasure room on the second floor. He secures his grappling hook and starts his ascent.
The rope he is using is knotted so the base difficulty is Average (d d ). Since he can help himself up the wall, the GM adds b to the pool. To reflect the danger and importance of the mission at hand, the GM decides to spend a story point to upgrade the difficulty. The rolls generates f h h dt.
Declan starts climbing up the rope. The GM decides to spend the hh to have a guard patrolling by. The guard notices the rope. The GM then spends the d to have Declan slip off the rope and fall. Declan’s player spends the t to fall directly on top of the guard, knocking them out. Now even though he possibly injured himself in the fall, he now has a guard’s attire he can use to enter the manor through the main entrance.
EXAMPLE #2 OF A CLIMB CHECK
Ignatious is exploring the northern mountains in search of a centuries-abandoned monastery hidden in this secluded part of the world. He now stands at a high altitude, buffeted by chilling winds. At some point, he faces a steep cliff he has to climb to reach higher summits.
The rock formation has only few handholds so the GM sets the difficulty of the Athletics check he has to make at Hard (d d d ) Athletics. The cliff has an unfavorable incline, adding b to the check. Fortunately, Ignatious has a climbing kit (Realms of Terrinoth page 100) that removes that b, however high winds at this altitude are strong enough to yet add yet another b to the check.
The roll generates shh. As Ignatious climbs his way up, he slips off, holding himself to the cloff only by his climbing axe. The GM spends a h to have his waist hit a pointy rock formation and make him suffer 1 wound. In addition, They spend the other h to make it so that when he hits the cliff wall, the lantern he had strapped to his back comes loose and falls, plunging out of sight. Ignatious curses as he knows he will need it later on, but he cannot afford to climb down and search for it. Yet, his s brings him up the cliffside where he fortifies his resolve and presses onward.