Not 100% sure that I got it, but if I may rephrase (correct me if I'm wrong): in principle, all actions by characters succeed (yay! I beat the Minotaur / I've climbed the wall, etc) — maybe unless the game master states otherwise — but it may exhaust your meta-character until it reaches d4 + your next roll below 4.
Another optional way I see (again, please tell me if I'm off-road) is to allow complete successes if the dice doesn't drop, and partial success if it does.
Saves are great, they are very helpful tactical tools when you need the story to move forward!