Yep, entirely right - 6-7 is a 'neutral fail' - you don't get to strike, but you don't get damage in the process either (or get minor damage if defending). 2-5 is a fail where the character receives damage, 1 is a critical fail where character gets MASSIVE damage. On the flipside, 8-11 is a success and the opposing character gets damage (or you don't get damaged while defending) while 12 deals heavy damage to opponent, both when striking and defending.
Of course - now that this is public knowledge, everyone may continue this particular fight without me should I be absent for a while.