The general game mechanic in Force On Force is that you roll a dice of a given type and any result of four or more is considered a Success. Some rolls however are 0pposed, in which case both sides roll a dice of their relevant type, and the higher roll wins. The problem is that the rules still talk about the 4+ result in relation to opposed rolls, whereas from what I've read in the forum, the intention was for this to be irrelevant for opposed rolls.
What then further complicates matters is that the rules writers then went on to use "pass the Reaction Test" as a synonym for "win the Reaction test" Overwatch units that "pass the Reaction Test" get to act before any other units. Since they also get a +1 on the Reaction Test roll, that means they'll be passing (4+) on anything other than a 1 or 2.
Replace that with what the rules writers seem to have intended and you have a much less severe Overwatch. Overwatching units now roll opposed Reactions as normal, with their +1 bonus, but have to beat the unit they're interrupting to fire first. If they don''t, then not only do they fire last, but they also lose overwatch status (by "failing" the Reaction test). Similarly, non-initiative units that "fail" a Reaction test aren't able to make further Reactions in the turn.
I can't find this explicitly stated in the forums or rules FAQ, but it tallies with the example of play and the assumptions stated by posters in the forums. Ambush Alley Games have nerfed my forum account so I'm waiting for a new one to be activated before asking some questions to definitively clarify these points, but I'm 99% confident that this reading of the rules is what the writers intended, even if it's definitely NOT what they put down in black and white.
Which to me is absolutely unforgivable, sloppy and incompetent rules writing. If you mean "win the Reaction test" say "win" not "passed". If you don't really care if either side rolls 4+ in an opposed roll, just who get's the highest total, then don't mention "rolls 4+ and beats their opponent" in the definition of winning. Define your terms, use them, and don't expect your reader to understand what you "meant to say" when you start throwing synonyms around.
If I'm right, then I'm liking this game a little more than the one we were playing over the weekend. But by God, it shouldn't have taken this much work to get there.