There is a nice 8 point still walking around in the area I hunt because i didn't use an armguard. Here's my new rule - Heavy clothing (winter jacket) = arm guard. I've practiced before with this jacket on and not hit the arm guard - but probably hadn't done enough practicing. I went home and shot many arrows and found very few times that it would hit, but there were definately some that would. Gotta love bowhunting - always plenty of opportunities to make a mistake for the first time - over and over again!