Economising on geometry for things such as game or even for simple architectural renderings in 3ds max

When designing for games or you just want to have a huge scene that looks very detailed without increasing the amount of polygons you can simply use the technique of texture baking. This process involves making a geometry with a very low amount of polygons then copying that geometry make it more detailed by adding in extra geometry and details in the geometry like holes etc. The render to texture dialogue in 3ds max allows you to do this by baking in details from the high poly object to the low poly object via maps such as the normal maps and lightmap which you will save out and then plug these maps back into the appropriate material map slots and apply it to the low poly geometry. It is a very simple process but puts you ahead of the game, check out this video which shows you the overall process.