Battles are won by slaughter and manoeuvre. The greater the general, the more he contributes in manoeuvre, the less he demands in slaughter.
This is a famous Winston Churchill quote, which I think can be profitably applied to D&D, further to the whole combat as sport versus combat as war thing; with just a few changes in terminology, we get the maxim:
D&D is won by slaughter and manoeuvre. The greater the player, the more he contributes in manoeuvre, the less he demands in slaughter.
A good maxim to live by. Good play is about cunning and careful manipulation of resources (be they mundane or magical), and the environment, to achieve maximum success with the minimum amount of death. Avoiding combat where possible, and, when necessary, using resources and the environment to bring maximum force to bear where the enemy is weak. Using the dungeon and wilderness to your advantage, in getting the maximum amount of gold and experience you can. Carefully marshalling equipment, using it when it is needed, improvising where necessary, making good logistical choices.
It is also about bringing snacks and, preferably, beer.