Setting "dynamic = off" keyframe for multiple active rigid bodies at once. I have multiple active rigid bodies which start to animate at frame 1 which is too fast. So to keep them still until the collision I want to keyframe "dynamic = off" at frame 1 and then change it to "dynamic = on" at 1 frame before collision. 

However I can't find a way to do it unless I individually click every rigid body and set their keyframes. This is problematic as there are more than 100 rigid bodies and now I am asking if there is a way to set keyframes for all of them at once.
try this:

Push space and just click the option called "Copy game physics properties to selected" And then it will copy the game physics to all selection one frame before they collide in your animation.

Good luck!