You are naturally resistant to Force use on your person. This cannot be combined with Force Aptitude and you may not be Force-sensitive at all! For each level, you get 1D to resist any Force use directed at your person. i.e. you cannot resist someone lifting up the floor beneath you, but you can resist them lifting up your boots! This also works against you as any friendly Force powers also suffer the same penalty, making it harder to heal you, etc.