sneak attack

[DARKJAY]

All weapon calls are made at the same time as the swing, strike, throw, discharge, etc.
You can make a courtesy call of "Archery" or "Thrown Weapon" if you think it will be clearer for your foe (such as when it is really dark or if you are attacking from behind).

Also, the B3 Packet Bows require a call of "Archery" or a skill call such as "Keen Shot".

But Heather is correct. You usually only would make a call if you are using an attack skill or there is a special property on the missile itself.