In Lord of the Flies, a complication occurs between Ralph's boys and Jack's boys. Ralph represents order and restraint while Jack represents savagery and evilness. Ralph desires to follow the rules of a civilized society. Jack gives in to an uncivilized state of mind. Jack becomes more than savage in his actions. He and his hunters enjoy torturing a sow. Roger twists his spear which is inside the anus of the sow: 

They corner the wounded pig, and when she falls they are on her. Roger is particularly cruel, driving in his spear slowly by leaning his weight upon it until the sow screams in agony. Then Jack cuts its throat.

The boys become hysterical as they seem to enjoy the agony that the sow is enduring:

Jack begins to rub the blood on his hands onto Maurice, and then they notice Roger withdraw his spear. They become hysterical because he had pinned the sow by driving the spear through its anus.

Clearly, Jack and his hunters have exposed their dark side. They have complicated life on the island. While Ralph is trying keep order and regulations as part of the process, Jack is encouraging his hunters to live dangerously as they expose their evil actions. They have no remorse for taking the life of a pig. Furthermore, Jack and his hunters decapitate the pig and leave its head hanging on a stick. 

Truly, Ralph is losing control of the boys. Jack is winning. Things are truly complicated on the island. It seems that Ralph is fighting a losing battle. He cannot get the boys to help him keep a fire going to signal a ship that may be passing by.  

Jack has become a god to his hunters. He is guarded and protected by his boys. He complicates things by making up his own rules. He enforces the rules with physical punishment. He leads by intimidation. He is rebellious. Through his intimidation and rebelliousness, Jack feels he is the only true leader.

By the end he is compared to an “ape” and called a “savage.”

In Lord of the Flies, what are three major complications in the story?

The major conflicts that arise in Lord of the Flies primarily occur between the boys as they try to survive their ordeal on the island. Perhaps the prime complication comes between Ralph and Jack in their battle for leadership supremacy. Although Ralph is elected leader of the stranded boys, Jack refuses to accept the democratic decision, and he eventually takes control through force and fear. Another conflict arises in the boys' perception of Piggy. The most intelligent and scientifically adept of the boys, Piggy's outward appearance--he is pale, overweight and has poor vision--is all the boys seem to see. His suggestions are usually denounced; even Jack, who knows that Piggy is his most loyal and trusting ally, takes him for granted, and Piggy is eventually killed. Another conflict comes in the form of the beast, which represents evil and which instills fear in the boys. Eventually, as Jack's hunters slowly grow less fearful, they decide to kill the beast and hang his head on a pole. This act completes the boys' total collapse into barbarism.