3D or 2D?

However, there are no generic solutions on engines. I helped a friend with designing a 2D (but hardware accelerated) RTS engine and it worked pretty OK.

I think you should try to learn some graphic API code and study some math first ( if you don''t already know all that ).

There is no use with a finnished complex engine for you if you don''t know all of it''s building blocks. So I would first create my own engine and then look at some samples to see what can be made different.

head over to www.gametutorials.com to learn everything that you will need in the opengl API. (Also, other usefull 3d Engine stuff are avalible there)

You don''t need to have 2d or 3d graphics in order to build/use a battle engine. ruellm didn''t say either way, but he could be building a text based RTS/RPG.

There''s many open-source RPGs (Arianne is one) on sourceforge.net. Try doing a search there and you''ll most likely find more than you want in just about ever different genre.

Also, if you don''t mind spending a little money, Jim Adams book "Programming Role Playing Games with DirectX" has some good stuff related to the development of a RPG style combat system. It''s pretty basic, but it will get you started if you are inexperienced.