Charanor's answer to your previous question already covered this point https://gamedev.stackexchange.com/a/212552/174134 However for clarity in the video (you cited above): * Dynamic - Green * Kinematic - Blue * Static - Red The effect when two objects "interact" depends on their types: | Ob 1 | Ob2 | Result | | ------- | -------- |----------------------------------------------- | | Green | Green | Collide: Both objects velocity is changed | | Green | Blue | Collide: Only Greens velocity is changed | | Green | Red | Collide: Only Greens velocity is changed | | Blue | Blue | No interaction - they just pass through each other | | Blue | Red | No interaction - Blue passes through Red | | Red | Red | Not possible - neither object is moving ** | ** - If they were initially placed overlapping, there would be no interaction. You can switch Ob1 and Ob2 columns - the result would be the same (hence I didn't bother with the duplicate lines). Changing the cited lines: > Kinematic bodies do not react to forces and only collide with dynamic bodies. > Kinematic bodies do not collide with other kinematic or static bodies To the colors in the video we get: > **Blue** bodies do not react to forces and only collide with **Green** bodies. > **Blue** bodies do not collide with other **Blue** or **Red** bodies The video only shows interactions involving at least one **Green** body.