Friendly fire

Aiming into melee and firing is perilous; not only is it -2 to -4 to hit, if you miss your target and the target is engaged with another party in combat you must also roll an attack against that party because of them providing partial cover to your intended target. (For example: if Fred the Fighter in your party is fighting an orc and you fire at the orc and miss, you then have to roll to see if you hit Fred instead, since during the combat he is providing partial cover to the orc from your attack.  Essentially, you may actually nail Fred instead of the orc.)