Rigid Body Physics
From RoboBlitz Editor Wiki
What is Rigid Body Physics?
TODO: Explain theory behind Rigid Body physics. Talk a bit about PhysX engine.
How to use Rigid Body Physics?
You should first make sure your object is set to use PHYS_RigidBody. This is the default for RDestructibles (which is probably what you should be using for your Rigid Body). You might also want to check bWakeOnLevelStart (it's in the RDestructible section) if you want your object to begin simulating when the map starts as opposed to when it's first touched by something else(you probably want this checked if the object isn't "at rest" at the beginging of the map). bWakeOnLevelStart will also make sure an object falls immediately if it's been placed in the air.
A few last thoughts
When an object explodes it applies force to other objects. If you'd like to adjust how much force is applied in an expolsion edit the exploding object's Destruction section in it's properties. ExplosionImpulseStrength is the value to change. ExplosionImpulseradius is how large of an area to apply the impulse.