malraux
First Post
So a level 1 PC doesn't need a 15 to climb a ladder and 10th level PC need a 25 to climb the same ladder. The PC isn't setting the DC. However, a ladder in a "level 1" zone is DC 15, while a ladder in a level 10 zone is 25, probably because its higher to climb, made of human bones, etc. If the level 1 ladder ended up shipped to the level 10 zone, it wouldn't become DC 25, mostly likely it would be ignored; its no longer a meaningful challenge to climb the 15 ladder unless there is a drastic chance of failure (since everyone can take 10 and they have at least a +5 from level).
More likely, in the level 1 zone, ladders are mostly available, while in the level 10 zone, the distances are too great to scale with a ladder and so the character needs to scale the rough wall. Even higher levels and the entire tower is made of glass and very hard to climb.