What is Conflict?
This is where we start getting into the meat of the story. Every story is about conflict, whether it is on a grand scale of world encompassing war, or someone trying to find their next meal to survive on, or even as simple as someone fighting their stomach over the decision of whether or not to have that second helping of pie after dinner.
The conflict however must be logical, going back to believe-ability again, in order for your audience to accept it. No one is interested in a story about two kingdoms going to war over the death of a fly, but if someone had killed a neighbor’s pig, well that could very well be an excuse for long term family feud, ala Hatfields and McCoys style. An epic story can even have an illogical foundation for the logical conflict, as in the case of Aladdin, who logically tries to win the heart of the princess, even though he only has the ability to do so due to the illogical process of rubbing a magical lamp and summoning an ancient genie.
Your story’s conflict should not be a simple progression from start to finish, but rather it should have several highs and lows, along with twists and turns built into it to keep things interesting for your audience. An example of this is the Lord of the Rings series by J.R.R. Tolkien (an epic storyteller if ever there was), where Frodo has a number of interesting conflicts throughout his journey. He has low points where he is separated from his allies and all alone, but then there are also high points when they reach places of peace and comfort like Rivendell. But these highs are followed by more low points, and on and on it goes. There are also a number of twists and turns to the conflict, at one point the conflict is against the orcs, at another it is against the creature Gollum, then against Frodo’s own desires to use the ring, then it is against a giant spider, or against his own party members who are fighting their own lust for the ring.
A truly epic story should also include at least one surprise twist in the narrative at some point. Your audience should not be able to predict the end results (or at least the path to it) right from the start. This surprise can also be about the protagonist or antagonist, but is generally revealed through the conflict. For example, you could surprise your audience by revealing that these reasons your protagonist hates the antagonist so much is that he is actually like them in some ways, like in I, Robot, where it is revealed that the protagonist is actually a cyborg.
Alternatively, you could have the antagonist reveal to the protagonist that the whole time they thought they were fighting him, they were actually helping him in some way or another, like in Total Recall, where the protagonist finds out that he accidentally led his antagonist straight into the heart of the resistance due to a secret tracker on him.