Slope Soaring - Is a branch of gliding that uses terrain features that create lift, rather than lift from thermals. Typically a steep hill face that has the wind blowing at right angles at it will have an uplifting airflow going up and over it. A glider can fly a cross wise pattern along the slope and gain altitude to well above the hight of the hill. The lift can be anything from gentle to violent, depending on wind speed and the angle of the hill. A cliff gives the most powerful lift, but also has a smaller lift zone than say a 45 degree angle hill.
Slope soaring models are often quite heavy for their size, weight 'can' be a bonus in strong lift as it translates to faster forward speed and more inertia for aerobatics.