Is it possible to automatically simplify geometry in blender without losing object shape? 3ds max has a sort of modifier that allows you to take a heavily subdivided mesh and take away some of the polygons that would anyhow create a single polygon (i.e they are facing the same way).
You could use the Decimate Modifier. You can find the documentation here. 
Please note that you only see its effect while in object mode.





You can find a 2 minute tutorial here.