You can override methods and functions:
Type Animal Field x = 320 Field y = 200 Method MakeNoise () Print "Thwwbbpppttt" ' Default sound... End Method End Type Type Dog Extends Animal Method MakeNoise () Print "Woof" End Method End Type Type Cow Extends Animal Method MakeNoise () Print "Moo" End Method End Type a:Animal = New Animal a.MakeNoise Print a.x Print a.y d:Dog = New Dog d.MakeNoise Print d.x Print d.y c:Cow = New Cow c.MakeNoise Print c.x Print c.y