Emphasizing this, for the opposite reasons stated by others. If you create a singular way to "win" a scenario, there's a very strong chance that your players will simply never see it. They will try everything else besides the "obvious" solution that you set up, and if you stick to it too strongly, it'll only lead to frustration for everyone.
In a way, Fate makes this incredibly easy to deal with.
- Problem
- Approach
- Resolution
- Aftermath
Hey, that could be a cool new acronym. Yay!
Sorry, I'll focus.
Basically, you present a
problem to the players. You can have a solution in mind, but don't fixate on it. If the players go another way, roll with it. Once the problem is presented, the players describe how they want to
approach it (or IF they even want to). Do they want to fight, sneak, talk, do a spell, etc.
Once that is set up, you know what both parties (Players and opposition) want and how they will go about it. At this point you can choose the
resolution mechanic. If your players want to sneak past someone, a simple roll or a contest could be enough, no need for a conflict. They could go and talk in a social conflict (or a simple roll again, if the person isn't too important in a talking way). You then go and resolve the scene the way the resolution mechanic demands.
And finally, you deal with the
aftermath. Different things happen depending on the outcome of the scene.
The approach bit is an important one (and one I sometimes forget myself. If you set up a cool opponent for a fight, you're kind of primed to go for a fight. But if the players have a cunning plan to sneak around that, you'll be robbed of that fight. At least sometimes it feels like it. So this is something to look out for and keep an open mind about. A non-conflict scene can be just as cool as a conflict, but it works very differently.
It also means that depending on the approach taken, the difficulties can be quite different. The two thugs might be pretty tough but rather dumb. You might be able to talk your way past them fairly easily, while fighting them would be a very bad idea. And other approaches to solve the problem can lead to scenes you might have never thought about.