One Sith could challenge another Sith for any reason, be it strife, anger, vengeance, greed or pure dislike. The challenger set the arena, whether a planet, a star system or the entire galaxy, and if accepted by the challengee, the ritual began. The two combatants employed the full force of their armies, bases and ships to outwit and outmaneuver their opponent in an attempt to defeat each other's forces.