# Is +1OB less significant than -1D?

From what I can tell, increasing the obstacle by 1 should be more significant than reducing the dice by one, since a dice has only a (usually) 50% chance of overcoming any obstacle.

I mean… increase an OB by 1 and the dice by 1, and ultimately, the character should have a higher chance of failure. Right? Just numerically?

So, why is it that in the Anatomy of Injury, superficial wounds do +1OB for 1 or 2 wounds, then replace with removing dice as it gets worse? And greater wounds just do dice reduction?

If I understand the math correctly, you should be more impaired by a superficial wound than a light wound. Or am I missing something? Thanks!

Also, sorry I keep posting and bothering you guys But I’m wanting to understand as much as I can.

-1D is closer to a penalty of +2 Ob, if I recall correctly. People that are good at math can probably explain why, but I know it’s come up several times. There are also some side-effects of losing dice, like having less opportunity to spend Fate, and becoming unable to roll skills that are reduced to 0 dice.

I don’t understand why this is true. The side effects, I 100% understand, but I don’t see how 1 dice is equal to 2 ob. Let me put forth some sample numbers to try to illustrate my question.

Let’s say you have an OB 2 challenge and a B4 skill. I’ve done the math for 4 dice - you have a 68.75% chance of success against an OB 2 challenge.

Subtract 1 dice and your odds of success drop to 50%

Let me illustrate this math real fast. With 4 dice, each dice has a 50% chance of success (4-6 success, 1-3 failure). Each combination (with F for failure and S for success) has a 6.25% chance of occurring (.5^4 is the math for that). So, 4 failures is only one combination - FFFF. That’s a 6.25% chance of occurrence. 3 failures has 4 possible combinations - FFFS, FFSF, FSFF, SFFF. That’s 4*6.25, or 25% chance.

In short, the array for B4 is as follows:

6.25 4F (or 0S)
25 3F (or 1S)
37.5 2F (or 2S)
25 1F (or 3S)
6.25 0F (or 4S)

And the array for B3 is as follows:

12.5 3F (or 0S)
37.5 2F (or 1S)
37.5 1F (or 2S)
12.5 0F (or 3S)

With B4, you need at least 2 successes - you succeed on 2 successes, 3 successes, and 4 successes. So 37.5 + 25 + 6.25, or 68.75% chance of success. With 3 dice, you succeed with 2 or 3 successes, or 37.5+12.5, or 50%. Those are against OB2. Against OB 3, those odds worsen dramatically - to 31.25%.

With this array (and other arrays), it seems outright fact that 1 OB is worth approximately 2 dice, as a rule.

I simply can’t understand how it could be otherwise.

Losing dice can put you out of a fight very quickly.

I’ll expand on stormsweeper’s message: -1D means one less action, one penalty closer to having a zero in a stat and being taken out, etc. And probably some other stuff I’m forgetting.

I tried searching the forums because this comes up a lot, but alas I suck at the search I guess.