Sacrifice in the context of King's Quest generally refers to the topic of human sacrifice/virgin/living sacrifice (or at least sacrificing members of ones own species).
King Graham is known for having sacrificed many virigin maidens of his kingdom to the Three-Headed Dragon... It was a yearly sacrifice to prevent total destruction of the Kingdom. Some say he agreed upon it on the advice of his prime minister, as well as the demands of the dragon itself. He even attempted to sacrifice his own daughter Rosella when his kingdom ran out of maidens to sacrifice (Valanice is said to have defied him standing with a sword at the door to Rosella's room before she ultimately gave up). She was later rescued that same day at the last moment by her long lost brother Alexander.
Since the Minotaur took over the Catacombs of the Ancients, it is one of the great sorrows of the kingdom that each year the minotaur demanded, and must be given, the living sacrifice of his choice lest he emerge from the catacombs and attack the city. The minotaur eats their young in sacrifice. A monstrous altar towers in one corner of the Minotaur's room, where the minotaur performs ritual at that sacrificial table. The Lord and Lady's own daughter, Lady Celeste, was taken there one morning as his most recently demanded offering, but thankfully Alexander was there to rescue her on the same day.
The Druids of the Isle of the Mist are also known for live human sacrifice and blood rituals to the great gods in order to control the weather. Alexander found himself to be the victim of one of these ceremonies when he was captured and put into a sacrificial cage during a Rain Festival to be burned alive, but survived thanks to a magical spell he had prepared in advance that put the flames of the sacrificial fires out with a rain storm. The great spells practiced by Druids on the Isle of the Mists are types of earth spell, most involve blood sacrifice. The Rain Festival is one of the most ancient and powerful of all spells--ablood sacrifice for fertility.
The farmers Tilly, and her brothers would offer sacrifices both human and animal to the Pit of the Laburnum to appease the creatures inside and avoid being attacked or eaten themselves. They have been known to sacrifice anything from travelers, soldiers, a half-dead troll, farm animals, and even their own dog in attempts to appease the Laburnum. Things changed for them when they attempted to sacrifice King Graham, and the bard Shallan, and their intended victims escaped the Laburnum. The Laburnum attacked the farm in retaliation, the brothers ended sacrificing their sister when she became too bossy and left their land for good.
The fire dwarves practice living sacrifices as well, and wanted to capture Connor to use him as their sacrifice.
The Magical laws of Opposites allow a wizard to manipulate one form of energy, matter, or simile in order to achieve its apparent opposite. An example might be the death of a sacrificial being in the attempt to create life in another. This is often associated with Necromancy.
It is said that if the river spirits did welcome victims of the River Fools, it is perhaps that they are as a sacrifice or as a warning against trespass.
Behind the scenesEdit
In Kingdom of Sorrow Graham encounters a somewhat similar story (to his own story of sacrificing maidens to dragons) of a family trying to protect their own lands by sacrificing innocent victims to rampaging monsters to appease the monsters... In the story, Graham is absolutely mortified and offended by this practice... especially as he learns he (and his friend Shallan) are their latest victims... Yet he doesn't make any reference to any similar practice occurring in Daventry to keep a certain dragon at bay... In fact Graham vows if he ever sees this family again they will be locked up in the Castle's darkest dungeon for what they have done (murder, kidnapping, and robbery)... If the Dragon was already rampaging in the kingdom at that time, it would make him a hypocrite on some level...
If the Dragon did come to attack Daventry it would have had to have taken place after Kingdom of Sorrow, and more likely after See No Weevi: that the attack by the dragons, human sacrifices and earthquakes probably occurred after after the latter book, as the kingdom seemed to be mostly peaceful, and no evidence of any dragon shown or mentioned. However, having Graham's sacrifices take place later in the timeline, doesn't avow him of the crimes in assisting the murder and kidnapping of innocent maidens to sacrifice them to the dragon, and still makes him a bit of a hypocrite when his views of the Tilly and her brothers are taken into consideration...