Campaign ideas (using Anniahlation movie as inspiration)

[Aaedimus]

Writing a module for an upcoming game, and I want to incorporate ideas and concepts from the movie Annihilation. I want to make it interesting, bring the wonder, fear, and survival into it.. as well as this weird sort of change, mutation, and rebirth.
I'd love ideas on how to incorporate this kind of stuff both:
1: narratively and
2: mechanically
(These are experienced players with a lot of trust, and we focus a lot on story, so messing with their character identities/abilities and core being isn't off the table).

[Dravda]

I haven't watched the movie, but I read the book a while ago. One thing I would do in writing a scenario like that is establish a set of rules (as strange and arbitrary as you care to make them), then enforce those rules consistently. Players will soon learn not to use their names, speak falsehoods, draw weapons, touch the color red, or anything else. I would telegraph some of these rules but not all of them, indicating to the PCs that while this place is strange, it behaves according to patterns and laws that they can learn and exploit.

Honestly, what Annihilation made me think of more than anything else was the SCP Foundation. If you're not familiar, this redacted entry (http://www.scpwiki.com/taboo) is an almost-perfect template for how I would run this kind of "otherworldly anomaly" scenario. If you're interested in a few more ideas, some honorable mentions include SCP-076 (http://www.scpwiki.com/scp-076), SCP-093 (http://www.scpwiki.com/scp-093), SCP-106 (http://www.scpwiki.com/scp-106), and SCP-087 (http://www.scpwiki.com/scp-087).

Good luck!

[micahaphone]

Travel doesn't work normally, i.e. if you keep walking straight down the same road you'll find yourself walking past the same locations again and again. Mention small details of the place so your players really know. "As you continue along the forest path, on your right you see a small abandoned inn, its sign hanging by one of its two chains and with 3 arrows stuck in it". If you want to make it creepier you can have small changes on subsequent loops, the building getting more ragged or rotten, a dark slime coating its timbers. To move "forward" towards your destination you need to split off from the path or take a side path that doesn't look like it goes the direction you want to move.

Depending on if your players have strong knowledge of the monster manual, you can mix/match descriptions and stat blocks, so an owlbear is mechanically just a kobold or goblin, spitting bone spikes instead of arrows, weakened by the new growth changing its body.


--------------------------------
second post edited in to avoid double posting:


For messing with characters stats, a corruption mechanic could be fun. keep a private track of each character, when they get 6 corruption points/incidents/etc, they privately get to choose a mechanical upgrade that comes with a cost. With each tier of corruption, they lose some of their humanity/normalcy. Could be a persuasion/intimidate/deception penalty at first tier, then later becomes ability score penalties. There is no way to turn back the clock on corruption.

Some random examples off the top of my head:

burning blood a la remorhaz but healing magic isn't as effective
a spell you can cast unlimited times, but each casting adds another tick to the corruption tracker
you gain a sharpness to your eyes/fingers/skin/organ, which imbues you with x but has penalty y. I'm thinking about the city of Anthe in Sunless Sea if you know that game. If not, here's a small wiki (https://thefifthcity.fandom.com/wiki/Anthe)
gain the ability to have resistance to psychic damage / advantage on a mental saving throw but each time you use this ability gain a point of corruption
Turn invisible or undetectable for x time (a turn, a minute), each time you use this gain a corruption point
Rapidly regenerate from wounds - As an action/bonus action, heal or spend hit die, but gain a corruption point each time this is used


I was reminded of this reddit post (https://www.reddit.com/r/bladesinthedark/comments/b5279e/adding_a_corruption_mechanic_to_bitd/)of someone coming up with corruption ideas for "Blades in the Dark"