Following up though, I will actually say though, part of the increased difficulty is because I don't necessarily want superheroes to be able to succeed on all challenges in an Action Chain easily; to some extent, the idea is to necessitate that they make tradeoffs and manage priorities. Superheroes should generally be able to succeed fairly easily at any given task, they're superheroes after all, but the challenge is truly in being able to do "everything". That being said, just the joint probability effect may be sufficient, and increasing the difficulty over the course of the chain may be overkill.