In the combat rules i wasn't able to find anything like the "attack of opportunity" of D&D. I mean a silent attack when the opponent is unaware of my presence. For example: I want to shoot an orc with my bow and he isn't seeing me. In this case, i think i should have a sort of bonus. What do you think?
I thought that an obvious possibility is not to consider the opponent Parry bonus; but what about his Stance TN?

P.S.: sorry for my poor language, but I'm not used to writing in english !

I think it would just be an attack against a TN of 12 (ignoring Parry makes sense)

But as you have time, you can do a Prepared Shot, making any successful attack the next round a Called Shot, which with a bow is a Piercing Blow, meaning an automatic Wound!

And in the Loremasters Book p65 it states that most adversaries are killed if they take a single wound, so unless the target makes a protection check.... it's dead anyway!

I think what you actually mean is a Sneak Attack or a Backstab, which are doable with the ambush rules.

Where do you find the ambush rules? I haven't read the Loremaster's Book Yet.

Check Loremaster's Book pg 43.

Very useful, thank you!
I think I'd better read the Loremaster's Book before posting another unuseful question .

The only stupid question is the one that goes unasked...keep asking, and we'll keep answering