Defeated Orc Hoards flee?
In many ways Gothic 3 simulates the behavior of NPCs quite convincingly. When attacking an Orc camp, after defeating a certain percentage of Orcs, the remaining Orcs will understand their defeat, give up and flee. This game mechanism is quite interesting, but can lead to unsolvable Quests. Example: In Nordmar, Osmund wants to get back an Ancestor Stone that a Shaman in a nearby Orc camp stole. Wiping out the camp will not work though, because the Leader and more importantly the Orc Shaman will hold back to the last, and then flee. Thus you loose the ancestor stone. Tip: Try to engage about 60 or 70% of the Orcs in battle, to weaken the camp significantly, then sprint away from the camp to let things quieten down, save the game, and then return to the camp directly attacking the Shaman.