To attach a RigidBody(Physics) to your scene entity, you will need to attach the Bullet - RigidBody Action to your entity.
To learn how to attach an action, folllow the MyFirstAction tutorial:
http://www.chi-ad.com/DokuWiki/doku.php/gs_firststeps5Instead of attaching a Rotate to your sceneEntity, choose the RigidBody.
Set its properties in the scene editor.
For the property Body Type, you can specify the following types:
those are the main ones, we arent sure the others are working.
Hope this helps