In general, when "you" do things in VR that you'd normally expect strong feedback for in your head, and you don't, you feel sick. Some examples: strafing side

In general, when "you" do things in VR that you'd normally expect strong feedback for in your head, and you don't, you feel sick. Some examples: strafing side to side (try it), going up stairs, any sort of sudden acceleration. Vive avoids this in room scale VR since you receive the feedback since you're really doing the action.