When should weaponry be used during mutual or non mutual combat?

Question

In a case where our assailants  are multiple ( three or four people  attacking one)

Or in a case where our assailant is 3 times our bodysize. 

Is it legally justifiable  for us to use a sharp object in means of self defense ie. knife?

Or any other object for that matter ?

Baseball  bat ,  beer bottle , poolstick , scissors  , Brick from the roadway   etc? 

Answer 1

If someone attacks you, you have a right to defend yourself. I prefer high velocity projectiles.

If you physically attack someone else they have a right to defend themselves from you.