What are the conflicts in Ender's Game?

There are a lot of internal and external conflicts present throughout this book.  I'll try to list as many as I can. 

• Ender's conflict with Bonzo.  This one ends with physical violence and Bonzo's death. 
• Ender's conflict with Stilson.  Like the previous conflict, Ender kills his opponent.  
• Ender's conflict with the commanding "officer" of each army that he is a part of in the battle room.  When Ender first gets to Battle School, no army or commander wants anything to do with Ender. 
• Ender's conflict with the other commanding officers once he himself gets control of Dragon Army.  Even as a fellow commander, Ender doesn't immediately gain the respect of the other commanders.  Ender also struggles to gain the respect of the soldiers assigned to his army. 
• Ender's real conflict and battle against the buggers at the end of the book. 
• Ender's conflict with Graff and other Battle School adults.  Ender knows that he's being manipulated.  
• Ender struggles with being a "third."  
• Ender struggles to remain good while knowing that he must at times be violent and cold like Peter. 
• Valentine and Peter struggle against each other regarding their plan to influence politics on Earth.  
• Valentine and Peter have a fake struggle against each other as Demosthenes and Locke. 
• Every time Ender steps into the battle room, he is in conflict against another army.  
• Ender struggles with depression as a result of feeling extremely isolated throughout various parts of the book.  

How does the setting influence the conflict in Ender's Game?

In Orson Scott Card's "Ender's Game," the children spent the majority of their time at Battle School, an isolated space station designed to educate them and train them in the art of war. This setting serves several purposes that impact the conflict of the story.

First of all, it forces the children into isolation and competition. By doing this, it accelerates the natural competitive structure of the children's lives. They are basically left in a militant organization with little structure above them, as the teachers and commanders are hands-off unless they are doling out punishment. The isolation forces them to work together or against one another.

Additionally, being in space, they are forced to work and fight in a low gravity environment, which prepares them for the space battles they will eventually encounter and helps teach them to think of new strategies.

The Battle School is constructed for the sole purpose of training children to fight in outer space. The children are not coddled or protected, but allowed to fight among themselves. The teachers deliberately set up the rules to pit the children against each other, in order to teach them strength of character and to see how they react.

"...you will get pushed around. And when you do, don't come crying to me. Got it? This is Battle School, not nursery school... If you don't like getting pushed around, figure out for yourself what to do about it..."
(Card, Ender's Game, Google Books)

Battle School is isolated and far from parents. The only authority figures are more interested in seeing how the children adapt than in protecting them, and so the children who don't get expelled become hard and cynical. Ender avoids cynicism for the most part, but the constant brutality makes him very pragmatic, which sometimes comes across in violence. Without the Battle School, which taught persistence through adversity through never playing fair, Ender would never have learned the lessons and the determination necessary to win the Bugger War.

What are Ender's conflicts in Ender's Game?

I think it is pretty clear from the very beginning of the story that Ender, through the course of this excellent scientific fiction novel, experiences any number of conflicts that seriously threaten him. First of all, a great place to start is considering how the series of external conflicts that he faces are all stage-managed to a certain extent, or observed. Note what the observers who watch him say at the beginning of the second chapter, after Ender has just beaten up the gang leader effectively:

"I went back through some of the tapes. I can't help it. i like the kid. I think we're going to screw him up."
"Of course we are. It's our job. We're the wicked witch. We promise gingerbread, but we eat the little bastards alive."

We cannot escape the disturbing conclusion that Ender is being formed by the violence that these observers either deliberately unleash upon him or sit passively by and watch him suffer. It is only through these experiences that Ender can gain the necessary skills and qualities necessary to save mankind, it is suggested.

Of course, Ender arguably experiences internal conflict as well, coming from the immense pressure he faces when he begins his "education" and starts playing the "Game." Ender's whole life is one massive exercise in conflict, which results in an individual who has been, in the words of the observers, "screwed up" or "eaten alive."