Originally Posted by .?.

There has been numerous reports from gamers who has experienced motion sickness in Half-Life 2, even those who play tons of games and never experienced this issue. Some people theorize that it is caused by the frame of view being set to 70 (as a reference, most FPS games have it set to 90.) Others say it?s caused by the default low refresh rate, and still others think it?s the physics of the world seeming to be so real.