The problem is the integration of difficulty modifiers with contested rolls.
The way it works now is simple enough. As per page 193, contested rolls are you rolling something and someone else rolling their thing, then you compare. Higher roll wins. Very simple.
We all know about fate points and Aspects and how those modify rolls. This isn't part of the problem, so it doesn't matter in this topic. This is because in contested rolls it modifies the roll, not the difficulty. So the math works out just fine.
Now, we have non-fate-point-driven modifiers. The rules for these start on 311. This section is a little hand-wavy, but it comes down to this: When factors are against you, the difficulty goes up, typically in units of +2. In a rush? +2 difficulty. Lacking some equipment? +2 difficulty. Very simple, again.
Now comes the problem. Turn to page 142 and check out the Stealth trapping Hiding. In a few words, it lays out the rules for hiding in a situation with difficulty modifiers from page 311. In short, you set the difficulty to hide, then your roll becomes the difficulty to spot you.
Why is this a problem? Well, low difficulties mean that low rolls can be successful. But that means that it's easier to spot you, because you rolled low. So your successful rolls, being lower, mean it's actually easier to spot you than if you'd rolled a barely successful roll against a higher difficulty.
For example, if the difficulty to hide is +0 and you rolled +2, it's easier to spot you than if the difficulty had been +2 and you'd rolled +3. Never mind that you've got 2 Shifts on the lower difficulty. You're easier to spot by 1.
This bugs me.
So I've come up with two simple ways to resolve this:
1. Modifiers to the difficulty during contests are multiplied by -1 and applied as a modifier to your roll. So a -2 to your difficulty (making it easier by 2) instead gets applied as a +2 to your roll (making it easier by 2). Likewise, a modifier of +2 to the difficulty (making it harder by 2) gets applied as a -2 to your roll (making it harder by 2).
2. Compare Shifts in contested rolls rather than the rolls themselves. If you beat your difficulty by 3 and the other dude beat his by 2, it doesn't matter that his roll is higher, because you have more Shifts. So you win.
They both accomplish pretty much the same thing: People can make contested rolls against different difficulties, and the degree to which you succeed matters. The first one sets all difficulties to the same baseline and the second counts degrees of success. These are more or less the same thing.
Thoughts?