Your Experience (XP) status is shown on the bottom of your HUD. By default, the game screen resolution is 1024x728. By allowing your resolution to be set this way, you can be given a accrutate reading of xp you have gained by seeing the yellow bar. By determining how much xp you have gained in order to level, you can point your mouse cursor over the bar. The Experience yellow bar shows your current progress and once the bar is filled, you have gained a level. Gaining Experience will gradually increase as you progress towards level 90.