Which will crash because the exe isn't linked with the binary at compile time.

Oh wait, He wants to combine un-compiled code into an already compiled program? Yeah thats just looking for trouble.

I thought he just wants to use a dll in his source, hence including the header file.

You understood it quite right, but from just including the header file the dll won't be linked automatically with his exe. Neither at compile time, nor at runtime.

Maybe I'm missing something

If you want to use an external dll in your program, you include the header file that accompanies it, compile it with the header file and then you can access the functions inside the dll.

I don't know, I don't use C/C++ very often Please enlighten me

I'm beginning to feel stupid it now, but let me repeat it again:

yeah, but engine opens the DLLs that use the plugin SDK automatically at startup, this is unrelated to including a header. As long as you define a prototype and call a function with same name and a matching signature that also exists in the DLL , it will use the function from the DLL.

Problem is: Esper already said he has no clue how to work with the plugin SDK and I doubt that there is any cryptographic library compiled against the Gamestudio SDK. So no automatic linking, just including the header and calling functions will fail.

Of course they will. There is still API macro but idk how much of help that will be for esper.