One thing to note here: Today I rolled a miss on a 96% chance three times in a row (standard attack with Lae'zel from behind). Now that is extremely unlucky, but I reloaded before each hit. On the fourth reload I used a different skill (the AE-Swing with the longsword) and that did connect. Because of the long reload times I did not reload again, but could it be that the outcome of the roll is calculated, for each skill, before you actually use it?
