This topic applies only to applications written in C++.

The IDirectPlay4 interface is the only interface you need for creating network applications that do not provide or require lobby services.

Dplay.h includes previous versions of this interface. These are included for compatibility with applications written for previous versions of DirectX.

• IDirectPlay contains the methods required to run applications that were written for the DirectX SDK versions 1 and 2. In addition, Dplay.h contains many defines and structures used only with the original IDirectPlay interface methods. Define IDIRECTPLAY2_OR_GREATER in your code or compiler in order to ignore these obsolete elements.
• IDirectPlay2 contains the methods required to run applications that were written for DirectX version 3.
• IDirectPlay3 contains the methods required to run applications written for DirectX version 5.0.

Although you could use any of these obsolete interfaces to create new applications, it is recommended that you use the newer IDirectPlay4 interface to take advantage of its increased functionality. It directly inherits from IDirectPlay3, so any code written for IDirectPlay3 will work with IDirectPlay4 with no modification. For more information, see Migrating from Previous Versions of DirectX.