Destroying objects HELP

hi everyone,
How I make objects be destroyed when shot with a cannon, but not destroyed at once when the they are hit, to be like on angry birds, if you hit the object directly and strong to destroy it but if you hit it bad only to be partly destroyed.
Can this be done?
Thanks for the help
How I make objects be destroyed when shot with a cannon, but not destroyed at once when the they are hit, to be like on angry birds, if you hit the object directly and strong to destroy it but if you hit it bad only to be partly destroyed.
Can this be done?
Thanks for the help

Comments
For hit points make a self.integer call it hitPoints and set it to say 5 and do a rule if it overlaps or collides with cannon change attribute self.hitPoints to self.hitPoints -1.
Then if self.hitPoints is lower than 1 destroy it.
Darren.