No. RF is extraordinarily simple in terms of calculations and there are no die rolls involved. Please, everyone, search the forums before spreading false speculation. The RF mechanism has been explained many times and these ill-informed comments only spread misinformation.
I don't mind at all how reaction fire works, but the information about how it works really,
really, should be available in-game. Either split up into several 'Tip of the day' segments, or some kind of Help section that doesn't yet exist. There could be a 'Game Mechanics' section in the UFOpaedia that spells out various basics of gameplay. Reaction fire is an integral part of how combat works, and it is not something the player should be left wondering about.
Failing that, it would be useful for that information to be easily visible on the wiki or on the forums in a sticky, rather than buried in some long-forgotten thread. If I enter 'reaction fire mechanics' or 'RF mechanics' or 'game mechanics' or other permutations of these things into the search bar, I ought to be able to find what I'm looking for, but I don't. The search engine of these forums just isn't very good - it doesn't prioritize keywords found in topic titles over keywords found in posts, and it doesn't prioritize a result with the entire search string just as you entered it over a result with the keywords strewn all over the place.
If this information was easily accessible, there wouldn't be so many questions and baseless speculations about it.
This isn't sufficient for the player to base an informed decision on.