Results of a set of Skill Challenges being invalidated by the DM, is this fair as designed or were the outcomes just poorly defined?

Question

Playing a low level/early stages 5e + homebrew game with a few friends. Though our DM is fairly new they have put in a ton of really amazing work at setting the scene for us these first few sessions.

However, they have also just put our cheery NPC tour guide that was introduced at the start of our travels in grave peril from a quickly approaching supernatural force. The creature and our NPC is about 200 feet away from the party at the start of the session and the NPC is frozen in shock or mesmerized.

We have no chance of beating or even distracting this entity with our attacks (we are told us as much in the introduction of the scene), and the DM says we are to do a set of skill challenges to get the attention of our petrified friend and have him run for cover/snap out of it/save him. We have some spells that could maybe work, like Message or Command, maybe a non-lethal attack to try and rouse him, but those are treated as non-applicable. We end up using some creative solutions focused on our proficiencies to pass the skill challenge with two failures and six successes.

The DM then just says, yeah, none of that worked you were too far away and the NPC sees you too late so the character is obliterated, there’s nothing left of him, just red a confetti of gore.

I get that they were hoping for and had written a downer, and that’s fine, it’s set in a kinda grim dark world and these things happen all the time. And I found it a bit comical as well as sad, but I think the thing that bothers and is still bothering me is the invalidation of our successes in the challenge and the limitation of our options. Feels like they have not honored the way the dice fell and the descriptions and performances we sold, and just went through with what they were planning on doing because they had written it that way.

Is this fair play as they designed it or an appropriate use of a skill challenge? Is it often that the results will be just struck down like that? I would prefer not to participate in another if that is the case.

If the creature had only cut him in half due to our success and then he later succumbed to his wounds, if he had died off screen and we found the body as a mystery hook, if the NPC was touched by it, corrupted, transformed and turned on us, those all seem like better ways to hook in a way that gives us a gameplay/action specific way to respond to it (I get that the DM may want our hook to be revenge).

How else might the skill challenge’s pass/fail outcome have been defined to make it both narratively sound and fair to us the players?

Answer 1

Railroading is not OK

From your description, it sounds as if you succeeded at the skill challenge, which the DM allowed as the only course of action that could influence the outcome

We end up using some creative solutions focused on our proficiencies to pass the skill challenge with two failures and six successes.

If by passing, you mean that you actually succeeded in the challenge, in spite of the two failures, and then the DM decided to get the NPC red-shirted anyways, that is absolutely not OK. In that case, the DM only fronted the challenge as a decoy in the hopes you‘ll fail it, and they can let the NPC die without you knowing there is nothing you could do. But if you have no chance to make it, they should not even make you roll. They should tell you there is nothing you can do, and kill the NPC, instead of giving you a faked illusion of agency.

And even if they determined you failed the challenge with these two misses, and you could have saved the NPC with successes across the board, it's also weak to not allow you other creative solutions that might make sense in the situation, and likewise smacks of railroading.

That the story emerges out of the the decisions the players take for their characters‘ actions and cannot be fully known in advance even by the DM is the heart of the role playing experience. Invalidating the players’ actions to have a railroaded plot play out is plainly bad DMing. The DM could be writing a novel if that is what they are after, instead of running a RPG game that turns the players into stage props.

These are rookie mistakes, and you say they are new at DMing, so these mistakes are understandable. They are certainly not the first to fall into that trap. But I would recommend they learn more about why this is bad. Here is a good starting point: What is 'railroading', and what are its pros and cons? and What is Player Agency and what is it good for?