You have 2 options:

1) You buy the InfinityEngine from BioWare (around 500.000 $)
2) You use the great Genesis3D engine. It''s completely free!

You could ask BioWare if you can rent it. It is possible. Or you get a "pay-less" version if you are a pupil/student/penner.

Kneelz.

The downside to making your own is that it can take alot of time just to make the engine. I have been working on my own gaming project and i have been writing and rewriting my game engine for 6 months. Other than networking I havn''t started on a single piece of core game logic because my engine isn''t finished.

The upside of using a premade engine is that you don''t have to worry about making an engine. You can go right into the core game logic and you don''t have to know a thing about DirectX or OpenGL.

The downside is you will have to spend time learning how the engine works. You will have to read tons of docs on which function is needed to do what and how things interface with each other. You will never get as good an understanding of the engine as the guy who made it and there will probably be tons of stuff you don''t need to use. Also, can you easily add stuff to the engine? What if there is a feature that you need and the engine does not support it?

My personal opinion is for something like a 2d RPG I would make my own engine. If you were making an FPS I would definetly consider looking into some different premade engines.

You could buy the Torque, a.k.a v12 or Tribes2, engine for $100.00 (www.garagegames.com). But that''s primarily 3d.