Jay Barnson on Unplanned Combat

Jay "Rampant Coyote" Barnson has written his thoughts on encounter balancing, and more importantly, how planning or lack thereof can drastically influence it on his blog, throwing in a few pen and paper anecdotes for good measure. Here's a snip:
This is a bone I have to pick with many RPG design. Combat often occurs at the player's convenience. Unless you are reloading from a previous save, you may not know exactly how it's going to play out, but the decision to risk combat is almost always in the player's control, normally via geography. You can hang out on the other side of the door all day long, resting, casting buffs, exchanging equipment, and nothing will happen until the moment you kick open the door. Or move into the area not currently visible on the screen.

This trend has led to a complete abandonment of things like resource attrition between combats. After all, if the player can simply rest outside the door to the monster's lair to get all their hit points and spells back, then why bother having that be a '˜thing' at all? Why not just set a cooldown guaranteed to pop between combats, and auto-heal the player when a fight isn't active? It's an obvious streamline if that's how the game plays. But then the same designers who make these decision struggle to figure out how to vary combat, and fall upon such goofiness as always having '˜waves' of attacking enemies. When all you have is a hammer, everything looks like a nail, I guess. Here's a hint: When a variation is used all the time to address a weakness of the game system, the variation ceases to be '˜variety' and all, and can get pretty tedious. Either come up with new ways of keeping things interesting, or un-paint yourself out of the corner and change the fundamental flaw in the system.

CRPGs have the (advantage) (if you want to call it that) of having the game force the encounter situation, preventing the player from optimizing tactics and preparation before the fight, to shake some variety into things. but I'm not so fond of forcing the player to be stupid like that.