Engine Royalty

It's worth noting that nobody but nobody does royalties this way. Divorcing the actual sale from the act of tracking opens up huge holes for alleging mis-counting, to the extent that IMO no developer with sane legal representation would touch such a thing with a ten foot pole. Royalties are tracked directly from gross receipts, with independent auditing provisions to keep everyone honest. Going a different way will probably result in zero sales.

If you want to distribute your engine for others to use, then I would suggest that you keep track of everyone who gets a copy by forces them to give you contact information before you give them your engine.

Now that you have their information you just need to make sure that everyone is being honest with what they are using it for. I don't think there is a way to know automatically when someone uses your engine.

Hi,
Sneftel is right here. Royalties on programs are not done that way.
There are other means to get paid for your work. If you look at other engines, you will see how they are priced. They try to get the money now, not on hypothetic sales of future games.

You could provide your engines with a level of services:
- you provide an engine for free either with reduced features, and/or with an inescapable engine splash screen so that potential customers can try out. There are no services associated. The engine can only be used as a dynamic library.
- you provide a full featured engine as a static library without the inescapable splash screen. You can have different prices according to the kind of customer you target (see FMOD pricing system, compare with un4seen BASS pricing system). You must also provide a hotline with the engine to help out developpers using the engine and to get direct feedback.

This is just an example. Compare with existing products and see how they are priced and what kind of services are provided for each price level.

Ghostly yours,
Red.