The game I'm running now is based on Swords & Wizardry. Originally we were using the Core Rules, but I quickly switched to the Complete rules once I found out they were actually available for free. There's practically no difference; Complete has a few optional classes, and it says a little bit more about Strongholds, wilderness, and monsters. All of the mechanics I've been able to track down are the same, though.
It actually started quite a while after the GURPS DF game finished; I and a couple friends from my former workplace went to a local con, and there I convinced them to play with me in a S&W White Box game. They loved it. For this reason I seriously considered sticking with the White Box rules, but I had done a few test runs with that system and knew I wanted to eventually move to something slightly more complicated, with things like variable weapon damage and hit points. I figured making the move at first was easier than making it later.
I rustled up two extras, two of whom had never played D&D before but were interested, and I gave them the choice: they could start in Hommlet or they could start in the Keep. They chose the Keep. Since I'm all about player choice, I told them that Hommlet was a few days to the east and that there were rumours of an old set of ruins a few days through the swamp to the south. (The Caverns of Thracia.) So far they've only been interested in the Caves, which is fine by me.
The setting is intentionally vague, and at least so far hasn't diverged much from the "medieval fantasy" background assumption of D&D. I'm running it like Points of Light, by which I mean the PCs are all from "the Realm" of which the Keep is the easternmost fortress, but the area they consider civilization they could walk across in a couple weeks. What else is out there? That's a good question, but it's not uninhabited. The Realm just considers them all "barbarians and savages with whom we sometimes trade."
A thousand years ago, The Empire collapsed as it was overrun by barbarian hordes. They left behind ruins, artifacts, etc. etc. The Church of the Realm is the Church of Sol Invictus. Alignments are based around this: if you're Lawful, you believe in Sol Invictus (or perhaps a related god, outside the Realm), civilization as a righteous thing, and all that. If you're Neutral, you don't really care one way or another. Perhaps you've lapsed, or perhaps you follow the Old Ways (druidic paganism). If you're Chaotic, you're opposed to Sol Invictus for some reason - maybe you don't believe in this civilization, maybe you worship one of the Darker Gods, or whatever. Notably, Magic Users are always chaotic, because the arcane forces they toy with twist them, and elves are always Chaotic because they're closely aligned with the Fae.
Generally, I'm going for a Dark Ages Europe feel. There's a Constantinople out there somewhere, but the PCs don't know about it.
Class levels also exist as an in-game phenomenon. In order to gain class levels, you travel to one of the 'navels of the world' - places of old power that the priests and scribes used to be controlled and sanctified by the Empire before it collapsed, and that are now sacred to Sol Invictus. If you go to a Lawful one, you come out either as a Fighter or a Cleric. If you go to a Chaotic one, you can come out as a Fighter, Cleric, or Thief. Naturally the Church doesn't admit that Chaotic navels (generally, those controlled by entities not aligned with Sol Invictus) exist, and they claim that the power of the navels comes from Sol Invictus. It certainly seems like they're partially right, what with Lawful Clerics getting blessings in line with the powers of Sol.
In order to become a Magic User, you find another Magic User to expose you to the secret artifacts and eldritch rituals.
Further, if someone has class levels, you can tell. They have a sort of mystical charisma and an air of competence - Fighters move with more grace and self-assurance than mere men-at-arms. Clerics are also obvious, and thieves are if they want to be, or to each other.
Anyhow, I have four sessions to quickly recap for posterity. I won't bother to make a distinction between the sessions at this point, but later I'll be writing recaps as they happen. (Mostly for my benefit. I don't like writing them, but they're a good place to stick information I need to keep track of that showed up in the session.)
When the curtain opened, we had:
Gim - a Lawful dwarven Cleric
Tiny - a Lawful Fighter
Pius Inebrius - a Chaotic Cleric who worships Bacchus
Elarion - an Elf Fighter/Magic-User
Buddha - a Neutral Cleric to a dead god
They spent the session meandering around the Keep, seeing the sights and meeting the locals. They heard a few rumours about the Caves of Chaos - like how the big dogmen live high in the caves, while the little dogmen live low, and how there's a huge vault of treasure in the southernmost caves, but also a wizard who would kill all trespassers - that I probably need to remind them of because it's been long enough I bet they've forgotten. They spent some time in the Traveller's Rest Inn, the name of the tavern and inn in the Keep, and recruited a few local laborers for their expedition. They also encountered the Curate of the Keep, along with the traveling priest and his two initiates, the latter group of whom readily agreed to go out with them to vanquish the evil in the Caves! These were Theodoric, Jovian, Bob, and Ted respectively. Those of you who remember the module know that Father Jovian is both Chaotic and evil, so he's coming along to make sure they fail and die.
Come the next morning they set out early, though they lost Buddha for a halfling ne'er-do-well named Pablo (who sports a Gordito moustache). They stopped by the Church for Theodoric's blessing, and he confided in Gim that he didn't exactly trust Jovian.
Off they went and promptly realized they didn't know where they were going other than 'off west somewhere near the road'. They turned north after about half a day on the road, cut through the forest, and finally found a very large clearing on the hillside. They set up camp because it was getting late, and resolved to keep searching come morning.
After a night-time diversion involving orcs that caused no casualties but netted no information, either (Jovian was the only one who spoke Orcish, and he wasn't about to tell the party that these guys were from the Caves or anything useful), they set about continuing to search. After a few hours poking through the clearing, Elarion found an opening into the hillside.
Again, those of you who know the module know that this was not the Caves of Chaos, but rather the Caves of the Unknown.
They gathered round the cave mouth and Tiny shouted inside. That's when the 28 stirges flew out and latched on to one of the laborers, Ted, and Gim. Fortunately for the party they were able to free Gim before he died. Ted and the laborer weren't so lucky, but at least most of the stirges stayed attached to them for the next few rounds, so the rest of the party managed to survive.
Entering the cave, they noticed immediately that it was quite strange, and very old. The stone was worked, but rather than being square, the walls, floor, and ceiling were all gently curved. The place also stank of ammonia and moisture, moreso when the short entryway opened into a large chamber with a tunnel northeast and another to the west that was clearly the place the stirges had been roosting. It also had a small raised area to the north, with a low rock platform that was strewn with the same bones and ammoniac junk that covered the floor. Examining this, they discovered that the thing was likely an altar of some sort, carved with bas-reliefs of snakes and other reptiles in various poses. They also found a small jade statue of a twining snake, which they took.
Deciding the take the northeast tunnel, they discovered that it opened into another smaller room at the end, with several molded wooden doors on the east, north, and west walls, and a pair of large corroded bronze valves ajar to the south. They set about busting down the nearest wooden door, which was still miraculously intact (carved with a snake sigil) but swollen into the doorframe. They sent Pablo in, where he found a large, dusty mess of what looks like it used to be plant fibers all over the room, a low dresser made of stone, and a low sleeping platform at the back of the room. The only thing of potential value he found was in the dresser - a mummified lizard, in the same drawer as a bunch of old stone knives and scalpels, some crusted with ancient blood. He pocketed it and moved on.
Meanwhile the rest of the party was looking around the main room and decided to bust down a few more of these doors to see what was inside. This much noise naturally attracted the interest of the basilisk in the next room, who came to investigate.
Basilisks in my game are very much what you might think - dog-sized lizards who turn creatures to stone. Specifically, you have to look the basilisk in the eyes, which themselves are made of large rubies. They're also immortal and don't need to eat, but constantly ravenously hungry (since most things they try to eat turn to stone before they can).
However, a properly alchemically mummified lizard is proof against this power, and in fact will turn the basilisk to stone if struck by one. Basilisks know this, and are mesmerized by the lizards when presented. (It's a sort of terror; the basilisk is caught between that and the ravenous hunger, and makes a save each round to continue attacking. I made up that mechanic on the spot.)
It took the party a good while to figure out the lizard was why Pablo wasn't turned to stone when the basilisk looked directly at him several times after he stabbed it in the kidneys. By that time, Jovian, Bob, and Pius had already turned to stone, and the surviving laborers had beat feet. It was still nearly a TPK, because they never figured out that striking the basilisk would petrify it. By the end, only Pablo and Tiny remained un-stoned, and Tiny only because he had his guts ripped out.
Fortunately, fresh basilisk blood is an antidote to petrification. It's also a very valuable alchemical reagent, mostly for Stone to Flesh unguents that manage to stretch it further. Pablo, being a worldly sort, knew this. He'd never slaughtered an animal before, but after a few mistakes he managed to get enough blood out of the creature for the four stoned party members to be reversed. (He got lucky; I rolled a d4 for doses. Originally there was a d8, but he wasted quite a bit of blood on the floor.)
After this, the party retired to lick their wounds for a week in the Keep. Turning back from stone is a physically stressful occurrence, and they needed some time off.
This post is getting really long, so I'm going to split the other two sessions off into another post. I'll also write up a little on the Caves of the Unknown.