The mapping works this way: If you use a power (at-will, encounter or daily), what happens in the game world matches the power description. But if you do not use a particular power, or a power that has an ambiguous description, you can describe what happens in-game however you want (though most will probably try to stay "reasonable", and not describe a simple basic attack as you jumping 20 feet in the air and crushing the enemies bodies into the ground, where he then stands up staggering... and takes 3 points of damage. )