DirectPlay is a deprecated API that was part of Microsoft's DirectX API.. DirectPlay is a network communication library intended for computer game development, although its general nature certainly allows it to be used for other purposes. DirectPlay, as the rest of DirectX, runs in COM and it is accessed through COM (Component Object Model) interfaces. By default, DirectPlay uses multi-threaded programming techniques and requires careful thought to avoid the usual threading issues. Since DirectX version 9, this issue can be alleviated at the expense of efficiency.