Just FYI, this really does work, and is infact the basis of the template design pattern. Where I went wrong: class A was written by somebody else (in this case it was part of WTL written by Microsoft). I thought it was virtual, it wasn't. If it was virtual it would've worked, as I've now found out. Why it works: The method in class B that calls the virtual function is calling it on the this pointer. Thus, the virtual table is used to figure out which version to call, so even though class B doesn't know about class C, class C's definition of the function is used. Pretty cool when you do it right.