hawkeyefan
Legend
This to me conflates two separate and disconnected issues: mechanics use and end satisfaction.
Sure, what happened from the NPC side was completely within the DM's power to control. And in hindsight maybe the DM wasn't too pleased with what he-she did with it and how it all shook down - we've probably all had those moments more often that we'd care to admit- but that's much the same as a DM making any other call and later realizing it could have been done better: live with it and move on.
Had some systemized mechanics been used there's nothing saying they couldn't have led to the exact same outcome, and what then? Does the DM blame the mechanics for leading to an unsatisfactory result?
So there have been a lot of posts since I was last watching the thread. I'm catching up now, but I wanted to reply to you in regard to this last bit of your post.
To go back to the trap example; let's say a PC searches the door (or whatever) and triggers a trap, and the DM decides, "there's no reasonable way you can avoid what happens.....your PC is dead."
I think many would argue that, under some "DM has final word" type of caveat, that this is well within what can happen at the table. But I know many folks, even those who might say that yes the DM can decide such, would be very annoyed if this is how it was handled at the table.
So the question is whether this is as preferable as the PC being allowed a saving throw, and then consulting the results of what happens on a success or failure of that saving throw? Such a system is in place to create a clear process about what happens under these circumstances. So when it does happen, it's understandable why it's happened, and it doesn't boil down to "the DM decided this is what happens". It's much more consistent in that regard.
I don't think that social interactions need mechanics for every little thing or anything like that.....but if PC execution is being put forth as a possible result, then I think having rules that allow for a clear process of how we end with that result is preferable to relying almost purely on DM whim.