Now this is muddying things for me, because if it is just a matter of setting the stakes, I don't really see what fail forward is. If it is a matter of taking a failure and turning it into something more productive for the adventure or storyline, that I can grasp. But in any game, the GM is setting the stakes for failure. To me fail forward sounds like it is meant to sidestep the initially set stakes (i.e. stake seems to be you tumble to your death or fall down the side of the mountain, but in actuality once the failed roll occurs, it is about losing a vital piece of equipment or not----so falling down the ravine was never really a potential outcome in hindsight).
I don't have a problem with that interpretation.
Bob is climbing Mount Pudding
Bob has to make a Jump to cross a chasm
Bob fails the die roll. Rolled an 8, needed a 10.
What does Failure mean (stakes?)?
A GM thinking simply, could assume that it's succeed and end up on the other side, fail and end up just short of the other side and fall into the chasm (taking falling damage).
Another GM could assume that there's variations of failure. What if you tripped on the run up to the ledge and haven't actually jumped yet?
Still another GM could be thinking "holy crap, this is the first challenge, we're 5 minutes into our gaming tonight and Bob just died."
FailForward could be viewed as a mind expanding tool for GM's 1 and 3 who need to consider that not everything has to be binary.
Personally, I see that sometimes, it's OK for Bob to fall, take damage and see what happens next. Other times, maybe I'd like to not kill him off in the first 5 minutes. Maybe he'll turn back if it's a near death experience. Or I can just yank his chain by making it harder now instead of killing him (which pretty much shuts down any fun).
I am pretty sure, that at some point, if Bob keeps jumping and failing, he needs to take damage. And eventually die. But that kind of game play is frustrating in video games (why I don't play platformers), and if falling and taking damage are the only possible outcomes of failing a jump, then that's jarring and damaging to immersion as well because of the lack of variance. Real failure is organic and variable.
So, depending on the situation, I'll throw Bob a bone and give him a setback instead of more boring damage. Heck, making him choose between fetching his wand that he thinks he needs or going on without it might stimulate better activity than my original boring material for 23 chasm jumps to reach the top...