Christian over at Destination Unknown prompted this post. He writes an interesting blog over there, I recommend you check it out.
He asks, what is the point of combat. He talks about his transition of opinion regarding combat and how his monsters & NPCs will now do everything in their power to kill the PCs. In a broader view, I maintain that players must worry about failure in the adventure or the adventure is no longer fun. If the tension created by the possibility of failure is gone, where is the excitement?
Failure is not limited to combat, and the consequences of failure are not limited to death. I maintain that players fear other types of failures more than death. The loss of prestige, the loss of treasured magic items, capture, or the loss of face by a notable villain usually generate more emotion than simple death.
Al over at Beyond The Black Gate says that character deaths are fun, and one of the notable differences between new and old school FRPGs is whether characters are disposable or not. He makes a interesting point about this difference. I see that both can be fun, and have had fun both ways. However, the game I want to play regularly does not involve disposable characters. Even when 1st Edition was our primary game vehicle, we didn't favor disposable characters.
So the dichotomy is this - I want to the players to fear for the safety & success of their characters yet I don't want a revolving door of new characters. I want to the players to be attached to their characters, but not so much they will not take risks. The game is only really fun when the tension of failure is palpable, when death, loss or embarrassing failure is perceived to be a real possibility. The players only achieve satisfaction if they feel they overcame the challenges and were not saved by the DM every time they were about to fail.
When characters are low level, every encounter should be difficult. They are at the bottom of the food chain and consequently they need to behave accordingly. As they progress, logic dictates that more and more encounters should not be a challenge to them. If as first level characters they are attacked by a raiding party of Orcs, it should be a tremendous challenge to survive let alone defeat them. Once they attain higher levels that same raiding party should be a cake walk - the characters hardly breaking a sweat as they deal with the Orcs. At higher levels the characters should be seeking more difficult challenges as motivated by their character goals.
As Christian points out, the verisimilitude is broken if the players understand there is a pattern or formula that allows the characters to easily defeat the opponents in every encounter. It needs to be more random, and encounters need to be plausible. As he says, why would 5 goblins attack 5 equipped adventurers? Unless they were out of their mind rabid, they wouldn't. So that is part of the challenge, creating plausible encounters where the 'monsters' believe they will succeed in their attack on the characters and can do everything in their power to do so. Anything less is unsatisfying to the players. Victory is hollow if there was no real threat.
The real challenge for the DM is to create those balanced encounters - balanced in the way the characters feel like it is plausible for the world in which they are playing, and threatening enough to make them fear for the characters they have come to love.
The dice never lie.