1: No shotgun ever runs out of ammunition. (Related law: Shotgun barrels
can be reversed on the fly so that the user takes the blast full in the
face.)
2: Supplies of sticks of dynamite and "bowling-ball" bombs are unlimited.
3: Baseball bats and other large bludgeons can be carried concealed in
one's hip pocket. (Corollary: All cartoon characters have hip pockets
whether they have clothes or not.)
4: Major implements of destruction -- steamrollers, tanks, and cannons --
can be produced on demand from out of nowhere.
-- The Laws of Cartoon Physics