I’m a first time DM and I struggle with this a lot haha. There are times where I feel a roll is appropriate, so I do it, and whatever is supposed to happen fails, then I realize… “what the hell is supposed to happen if that doesn’t work?” so it just kinda happens anyways… IDK if my players have caught on…
I learned in my first adventure that what I’ve prepared to happen might just be stupid and unrealistic, so I’m never too attached to it. If the dice say it doesn’t happen, they know better than me, so I just toss it. If I lie about the dice to make it happen anyway, I’m making a worse experience for everyone.
If a failure means a path is unavailable, see if you can open up a different path. If there are no other paths, just let them have this one for free.
You could just skip the roll, because if failure is unacceptable then it isn’t appropriate.
That’s where my problem comes from. I’m not experienced enough to know immediately where failure is acceptable or not; rather, I don’t always have backup plans or ideas for when things that should be able to fail, fail. So I roll, and it fails, and it should fail, but I’ve got no idea what happens when it does. So it doesn’t fail.
I think I’m getting better at improv-ing events and making backup plans. It’s still difficult for me to find the balance between the story I want to tell/ have prepared vs the story that my players wind up creating, but checking in with my party here and there tells me everyone’s having fun and only rarely does anyone feel gipped or abused by dice rolls.
Prior to rolling, think about what will happen if the roll fails or succeeds. If you are worried about failure at all, that is a good sign that failing is probably not an option. Basically, if you are able to make the decision to fudge it when it happens you had the same time frame to decide notnto risk that need to fudge in the first place.
Over time with more experience you will find ways to make failure a bump in the road to fun tims.