As per title, I don't remember (and thus I'm unable to find) where I've read this rule. It may be a 3/3.5 leftover, but I have a blurred reminescence of reading it in Pathfinder some months ago.
The rule is: when you have two creatures confronting in something that involves a more or less prolonged use of an ability score, such as arm wrestling, you don't roll a d20 as you would for opposed skill checks, unless they have the same bonus in the relevant ability score. If the two have different bonuses, whoever has the highest one wins without rolling anything.
Does anyone remember where it's written, given that it really is?
I do not recall anything like that, even in 3.0/3.5. It might be optional rule from some strange book or house rule.
From the d20 SRD: Ability Checks
I do not see a similar rule in Pathfinder.
That's it, thanks.