I like a lot of the rats stuff. Disease, the threat of tunnel collapse, and especially the nibbling on extremities of players caught in traps. It's funny -- it's still 1d6 damage, but "they're eating my hand" is so much worse than "oof, not another arrow trap."
On the subject of disease. I'm playing right now in a campaign that has changed how I look at disease. The thing to remember about the PCs is that they are communicable. We are currently in the middle of the black death, and we don't dare to go to town to get a cure disease cast, because we'll kill the whole town.
Further, the omnipresent plague makes a great D&D setting. Think about it: roving bands of looters (read: adventurers), no effective centralized authority, occasional "points of light" safe harbors, lots of loose treasure, bandits, monsters run amok. All of the wierd aspects of D&D are explained by having the players struggling to survive in the midst of the Black Death.
Chad --
I've been trying to build lethality into the game. I think players get bored with no risk. Player death creates tension and builds credibility. (Credibility is also why I do open rolling -- if the monster rolls a crit, you are toast.)
The first thing I do when I start a campaign is I decide which adventure I'll run if there is a total party kill. I try to make the adventure as good as possible. (You have to make it scaleable, so that you can run it at any time). Then, I put the adventure in my back pocket.
Having the adventure ready to go means that you won't hesitate if a kill happens. You know that the game will go on--that the game will in fact *BE BETTER* if they die. Because you put a lot of thought into it.
In the kobold lair: the players are prisoners in a
debtor's prison. The prison is built in an ancient city, atop the rubble of many prior civilizations. The prisoners dig, and break through into the lair, which has been sealed for millenia. Eggs start to hatch, and prisoners start to disappear. The PCs, in Cell Block Six, are chosen by the rest of the prisoners to investigate and stop the killing.
Planning for death: This is the first arc in an
Antihero campaign. If the PCs are killed, I plan to have them wake up in the corpse-pits of the city, each with a blackened silver piece clutched in their left hand, and sickening voices in their heads. These
pieces of silver (look at the Order of the Blackened Denarius) are central to the story line--the deaths, and the mystery surrounding them, are what I hope will drive the campaign.
And, on a different note, an idea:
Surprise. The surprise round is a wierd artifact. I wonder if we couldn't use the mechanic a bit more. With some emphasis, the surprise round could really become a way of ramping up the terror of "gotcha"-style creatures.