There are a few sets of tactics that Ender uses to achieve a significant battlefield advantage. They seem applicable to real warfare.
- "The enemy's gate is down" (I) - Possessing high ground and favourable ground has been a military maxim for success since Sun Tzu and before.
- "The enemy's gate is down" (II) - Don't hesitate to strike at the heart of the enemy's defences if you feel that you can decapitate their leadership.
- "The enemy's gate is down" (III) - Viewing the battlespace from multiple perspectives can provide unexpected insight.
- Constantly innovate - Seen when he allows his toonsquad to use wires for flight, different types of loose formations, giving toon subcommanders leeway to fight how they see fit, etc
- Formations are for suckers (mostly) - If your enemy knows where you are, it gives them a huge advantage. Subverted when Ender uses a formation at the end of his time at Battle School
- Know your enemy - Ender spends countless hours studying the way in which the bugger fleet fights, in order to understand how best to fight them.
- Destroy your enemy utterly and then you don't have to worry about having to fight them again - Seen a few times in the book, notably when he commits mundicide.
Interestingly, the Marine Corps recommendation (which sparked this question) seems to feel that the core values of the book aren't military in nature, but rather that it should be read in order to understand the loneliness of command and what it means to retain your humanity while fighting.
In this science fiction novel, child genius Ender Wiggin is chosen by international military forces to save the world from destruction by a deadly alien race. His skills make him a leader yet Ender suffers from isolation and rivalry from his peers, pressure from adults, and fear of the enemy. His psychological battles include loneliness and fear that he is becoming like his cruel brother. The novel’s major theme is the concept of a “game” and all of the other important ideas in the novel are interpreted through this concept. Some of the important ideas in the book include: the relationship between children and adults, compassion, ruthlessness, friends and enemies, and the question of humanity: what it means to be human.