Challenges for the climb to a vampire's manor

[kieza]

I'm about to run a game for some first-time players tomorrow, and I've just realized that the adventure I wrote dives into combat too quickly. I need a couple of non-combat challenges that I can work into the adventure without too much prep.

The adventure runs like this:
--The party is a band of semi-heroic adventurers who've banded together in a place called Der Eisenwald, a heavily-forested, mountainous region filled with vampires, werewolves, necromancers, mad scientists, and everything else from the Hammer Horror ouvre. It's one part Hollywood Transylvania and one part Hollywood Bavaria.
--They've been following some strange, confused rumors about unearthly happenings at a remote village: something involving lightning strikes and unsettling music.
--The castle overlooking the village used to be occupied by a nest of tyrannical vampires, but they mellowed out about a hundred years ago, and it's been abandoned for most of the last century.
--The actual danger is a mad scientist, who is squatting in the castle. The villagers aren't sure what he intends, but he's playing ominous music at night, and something he's doing is causing lightning to strike upwards from the castle.
--The devices causing those phenomena are merely diversions from what the mad scientist is working on presently: he's experimenting with vampiric lore, and the blood-bound wights that the vampires left behind, to create a device to emulate the powers of vampirism with none of the drawbacks. As a side effect, he is also weakening the bindings which hold back the vampires' ancient progenitor, who they got fed up with and left locked in his coffin, deep beneath the castle.

What I need are some challenges that I can insert on the journey up to the castle, like figuring out a way past the raised drawbridge. A vampire-themed puzzle would work great.

EDIT: I had a eureka moment right after posting this. Here's the riddle I thought up:

At the edge of the village, where the road up to the manor begins, there is an archway inscribed with the words "The way is barred with the blood to which four-by-two may be joined, and it shall only be opened by that which must remain undiluted.” There is a sharp metal spike attached to one pillar of the archway, and beneath it is a stone basin. If anyone passes through the arch, it triggers an immediate response: the wind picks up, clouds form in the sky, and bats swarm from their caves. If anyone tries to continue up the road, the weather becomes progressively worse, and ground beneath their feet seems to fight them, causing them to slip and stumble whenever their attention wanders.

To pass through the gate and up the road unhindered, they must spill blood in the basin. Specifically, they must spill type O- blood, which cannot be diluted by receiving a transfusion of any other type. "Four-by-two" is a reference to the four *** blood groups (A, B, AB, and O) and two Rh blood groups (+ and -). Type AB+ blood can receive a transfusion from any of the eight combinations, and it was used in the enchantment barring the way. There is a way to search out O- donors by performing an impromptu blood test on the party and the villagers, involving a combination of Arcana and Medicine checks, but they can also brute-force the enchantment by having everybody available shed some blood: there's no penalty for spilling the wrong kind into the basin.

Any thoughts?

[Keltest]

I think any sort of riddle is just going to frustrate the players. Maybe your group is different, but anything that tests the out of character player's problem solving skill instead of their in-character strengths and weaknesses tends to bother people in the groups ive played with.

So to that end, lets ask ourselves a few questions about who designed these defenses and what they were meant to keep out?

We can allow ourselves a few assumptions as well. The scientist himself has to be able to get in, so anything that automatically precludes mortals should be deactivated. He almost certainly has minions or servants as well, but they aren't necessarily human or alive, and they should be able to come and go as needed.

So how many of these defenses were designed by the vampires versus the scientist? Is he trying specifically to keep the vampires out, or just meddlesome villagers? What kind of staff does he have, and how frequently does he himself come and go?

[Monkeyknuckles]

The approach to the castle is a good time to drop clues as to what's really going on inside
Perhaps a drain dribbles necromantically charged blood down the cliff face where the players can interact with h it and note it's unusual properties. They could have an RP interaction with a disgruntled lab assistant burrying the remains of a failed experiment . There could be an angry mob armed with torches and garlic willing to pay the players to get the gates open for them to do some old fashioned anti-vampire mob violence to.

[Brookshw]

It relies upon OOC knowledge as well as seem anachronistic to a D&D setting. I wouldn't recommend it for that alone, though if you did decide to press on with it you should probably be dropping some hints along the way a'la NPCs that blood types are even a thing and important. Otoh, doing a lot of foreshadowing just for a puzzle seems like a lot of time wasted that could be put to better use.

Alternatives to consider:
Part of the drawbridge mechanism is missing, why is that and where did it go?
Various other means of ingress, caves or underground rivers that lead into the castle, players can discover and figure out ways to traverse them to gain entry.
Use a different puzzle, maybe "cast no shadow, ye who would come in peace" (go at night without a light source or something else), things that don't require Player knowledge.