Dynamic

Once activated, this gives your object real physics properties. Your object will now be pulled by gravity, bounce off other objects, have mass and be slowed by friction.

Settings

Actor: See Here
Ghost: See Here
Invisible: See Here

Use Material Force Field

This causes your object to interact with Dynamic Materials. This is currently not supported by the default bullet physics and is not fully supported in the Sumo engine in the current edition of Blender. It is fully supported by version 2.24 of Blender.

Rotate From Normal: Use face normal to rotate object, so that it points away from the surface.

No Sleeping: By default if an object that is affected by rolling physics comes to a rest, Rolling Physics is disabled. The physic engine assumes that it no longer needs to calculate the object’s motion. In some case this is true and will save you processing power, in other case such as in a soccer game, the physics needs to be maintained until someone kicks the ball placing it back in motion.

Attributes

Mass: Mass affects the amount of force that is required to move an object. The greater the mass the greater the force that need to be applied to the object in order to move the object. Mass will not cause objects to fall faster or slower. To slow an object down use dampening, if you wish to accelerate the falling rate increase gravity (normal gravity is 9.81).

Radius: This determines the size of the bounding area for sphere bound objects and Fh/FhRot. This can be changed to a large or smaller size to give your object the look and feel you desire. The shape of the bounding area is determined by the Bounds button, by default it is a Box.

When changing the bounding size you can see the effect on the screen, in the shape of a circle. At this point in time all bounding shapes are reflected as a circle in the 3D window, even though they react differently during the game play.

Form Factor: The Form factor gives you a degree of control over rigid body objects. The higher the Form factor, the less likely an object is to roll, especially rolling on a flat surface.

Anisotropic Friction: See Here

Velocity

Minimum: Clamp velocity to this minimum speed.
Maximum: Clamp velocity to this maximum speed.

Damping

Translation: Dampening affects the freedom of an object to move. In space there should be almost no dampening, while in water the dampening should be set quite high.

Rotation: Rotational Dampening is the same as dampening but only affects the object’s rotation. A high Rotational Dampening will not affect the rest of the object’s momentum.

Lock Translation and Rotation

You can limit an object's rotational and translational axes to any combination of the X, Y, and Z axes.

Collision Bounds

See Here.

Doc:2.6/Manual/Game Engine/Physics/Object Type/Dynamic