My 3D hardware supports edge/full-scene antialiasing (I know this because I''ve seen OpenGL programs do this on my computer.) However, I write games using the DirectX 6 API, and I can''t get any edge/full-scene antialiasing to happen at all. Is there some trick to what render states I should set, or should I upgrade to DirectX 7?

Did you check your device caps for sort dependent/independent? When I checked that my full scene antialiasing worked. Also, I''d upgrade to DX7. I did.