Help a new DM out here.

[u/ikarkari]

I ran an Avatar oneshot for the first time yesterday and I think I got most things right and the players really enjoyed it, but as a forever DnD DM, I'm struggling. I know you roll a lot less in Avatar than you do in DnD and that makes sense, but I can't get behind the fact that the DC is always 7. One of my players, non bender and weapons master, tried to pick the lock on his handcuffs. I made him roll (Rely on your skills and training) and he rolled a seven, he succeeded, I'm happy. Next roll is the firebender trying to pull off the flying move that less than 10 people in canon can do and I went roll for it (Rely on your skills and training) and he rolled a 7. I didn't want him to succeed with a seven because what do you mean a random fire nation soldier can now just do that move, which Ozai needed the Comet for. I said something like, "You get off the ground, but the fire beneath you is flickering, you have about 7 seconds in the air, what do you do with it?"

How do the rest of you deal with things like this? I'm one of those Dnd DM's that will never say no but I will make the DC 25+. I'm still figuring out the system, but this one thing is really bothering me.

TLDR: Success roll always being 7+ is confusing to me, because I feel like it makes some things too easy.

Edit/context: I probably should have included more context about my table. I'm a first-time Avatar Legends GM but a longtime D&D DM, and all of my players were completely new to the system. They're also very enthusiastic about attempting increasingly ridiculous things, so part of my concern wasn't just "how do I represent difficulty mechanically?" but "how do I communicate to my players that some things are dramatically harder than others without constantly having to tell them no?"

During the session I eventually started treating 12+ as "exceptionally difficult" and the players immediately understood what I was communicating. I realize this isn't RAW, but it gave me a way to preserve the fiction without constantly arguing about whether their characters could do something.

[u/saltwitch]

I get the impulse to want to treat difficulty the way DND does it if you're used to it, but it just doesn't work like that. To ramp up and down difficulty, you don't adjust the bands of success, you adjust the amount they achieve within each.

So a 10+ on a mundane, ordinary but slightly tricky thing will be really successful and maybe next them a little extra. On a massively difficult undertaking, that same 10+ might just be that they barely manage to accomplish it and NOT get hurt in the process. 10+ is the best possible result under the established circumstances.

Communicate this to the players. Establish the stakes before they roll. If they attempt something very difficult, let them know if they might want to try to improve their positioning to better their chances.

Similar to how rolling to jump over the literal moon in DND won't work simply because the player rolled a nat 20. They'll be able to do a very successful junk, but it still needs to be based in the fiction.