Let me know more about the system and i'll see what i can do about joining. I've looked at the book only once.
First off:
<a href="http://www.goodreads.com/book/show/64251.Mouse_Guard" rel="nofollow">http://www.goodreads.com/book/show/64251.Mouse_Guard</a>
If you can find it. Read it. It's good and will give you a better understanding of how hard it is for these little guys.
I'm not sure if I can do it justice but i will try....
Well first of all it's *based* off the burning wheel system.
Beliefs, Instincts, and traits are descriptions of your character you make up which has an actual game mechanic affect. And is the real strength of the Mouse Guard system.
It's a dice pool system. So if you have a strength of 2 and a sword skill of 3. You have a total of 5 to swing that sword. So you roll 5 dice. Any dice that rolls 4 5 or 6 is a pass. More passes are good. You gain experience for a skill as you use that skill rather than exp at the end of the night.
With the exception of how the dice work. Skills are like DnD. The fight system is nothing like DnD. And the conflict system (is/can be) used for fighting, whole battles, arguing, lying, tests of strengths or will,...and...one of the best parts; CHASING! So you can have a much more dramatic chase scene rather that both of you moving 30ft per turn. And with this system lying to someone can very on how much they believe you. Rather than DC passed or not.
And the best part, is conflict rules are fast...very fast once you get the rhythm of it.
You gain persona points and fate points which can be use to affect the dice rolls and story which is cool.